diff --git a/csharp/src/AddressBook/Addressbook.cs b/csharp/src/AddressBook/Addressbook.cs
index 2fb6be835..2b4302620 100644
--- a/csharp/src/AddressBook/Addressbook.cs
+++ b/csharp/src/AddressBook/Addressbook.cs
@@ -155,7 +155,7 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
       if (Id != 0) hash ^= Id.GetHashCode();
       if (Email.Length != 0) hash ^= Email.GetHashCode();
@@ -200,6 +200,7 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
       }
       return size;
     }
+
     public void MergeFrom(Person other) {
       if (other == null) {
         return;
@@ -329,7 +330,7 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
         }
 
         public override int GetHashCode() {
-          int hash = 0;
+          int hash = 17;
           if (Number.Length != 0) hash ^= Number.GetHashCode();
           if (Type != global::Google.ProtocolBuffers.Examples.AddressBook.Person.Types.PhoneType.HOME) hash ^= Type.GetHashCode();
           return hash;
@@ -356,6 +357,7 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
           }
           return size;
         }
+
         public void MergeFrom(PhoneNumber other) {
           if (other == null) {
             return;
@@ -456,7 +458,7 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       hash ^= person_.GetHashCode();
       return hash;
     }
@@ -477,6 +479,7 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
       }
       return size;
     }
+
     public void MergeFrom(AddressBook other) {
       if (other == null) {
         return;
diff --git a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportProto3.cs b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportProto3.cs
index a32d19c23..6b779ed5c 100644
--- a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportProto3.cs
+++ b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportProto3.cs
@@ -120,7 +120,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (D != 0) hash ^= D.GetHashCode();
       return hash;
     }
@@ -139,6 +139,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(ImportMessage other) {
       if (other == null) {
         return;
diff --git a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportPublicProto3.cs b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportPublicProto3.cs
index 2c8b0a310..a922bfac6 100644
--- a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportPublicProto3.cs
+++ b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportPublicProto3.cs
@@ -105,7 +105,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (E != 0) hash ^= E.GetHashCode();
       return hash;
     }
@@ -124,6 +124,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(PublicImportMessage other) {
       if (other == null) {
         return;
diff --git a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestIssues.cs b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestIssues.cs
index 28508a3bd..280e71c64 100644
--- a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestIssues.cs
+++ b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestIssues.cs
@@ -168,7 +168,7 @@ namespace UnitTest.Issues.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Value != global::UnitTest.Issues.TestProtos.NegativeEnum.NEGATIVE_ENUM_ZERO) hash ^= Value.GetHashCode();
       hash ^= values_.GetHashCode();
       hash ^= packedValues_.GetHashCode();
@@ -212,6 +212,7 @@ namespace UnitTest.Issues.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(NegativeEnumMessage other) {
       if (other == null) {
         return;
@@ -303,7 +304,7 @@ namespace UnitTest.Issues.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       return hash;
     }
 
@@ -314,6 +315,7 @@ namespace UnitTest.Issues.TestProtos {
       int size = 0;
       return size;
     }
+
     public void MergeFrom(DeprecatedChild other) {
       if (other == null) {
         return;
@@ -456,7 +458,7 @@ namespace UnitTest.Issues.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (PrimitiveValue != 0) hash ^= PrimitiveValue.GetHashCode();
       hash ^= primitiveArray_.GetHashCode();
       if (messageValue_ != null) hash ^= MessageValue.GetHashCode();
@@ -527,6 +529,7 @@ namespace UnitTest.Issues.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(DeprecatedFieldsMessage other) {
       if (other == null) {
         return;
@@ -655,7 +658,7 @@ namespace UnitTest.Issues.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Item != 0) hash ^= Item.GetHashCode();
       return hash;
     }
@@ -674,6 +677,7 @@ namespace UnitTest.Issues.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(ItemField other) {
       if (other == null) {
         return;
diff --git a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestProto3.cs b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestProto3.cs
index e0d0d3d0e..8d8796176 100644
--- a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestProto3.cs
+++ b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestProto3.cs
@@ -1058,7 +1058,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (SingleInt32 != 0) hash ^= SingleInt32.GetHashCode();
       if (SingleInt64 != 0L) hash ^= SingleInt64.GetHashCode();
       if (SingleUint32 != 0) hash ^= SingleUint32.GetHashCode();
@@ -1544,6 +1544,7 @@ namespace Google.Protobuf.TestProtos {
       size += mapBoolToEnum_.CalculateSize(_map_mapBoolToEnum_codec);
       return size;
     }
+
     public void MergeFrom(TestAllTypes other) {
       if (other == null) {
         return;
@@ -1992,7 +1993,7 @@ namespace Google.Protobuf.TestProtos {
         }
 
         public override int GetHashCode() {
-          int hash = 0;
+          int hash = 17;
           if (Bb != 0) hash ^= Bb.GetHashCode();
           return hash;
         }
@@ -2011,6 +2012,7 @@ namespace Google.Protobuf.TestProtos {
           }
           return size;
         }
+
         public void MergeFrom(NestedMessage other) {
           if (other == null) {
             return;
@@ -2115,7 +2117,7 @@ namespace Google.Protobuf.TestProtos {
         }
 
         public override int GetHashCode() {
-          int hash = 0;
+          int hash = 17;
           if (Key.Length != 0) hash ^= Key.GetHashCode();
           if (value_ != null) hash ^= Value.GetHashCode();
           return hash;
@@ -2142,6 +2144,7 @@ namespace Google.Protobuf.TestProtos {
           }
           return size;
         }
+
         public void MergeFrom(MapStringToNestedMessageEntry other) {
           if (other == null) {
             return;
@@ -2258,7 +2261,7 @@ namespace Google.Protobuf.TestProtos {
         }
 
         public override int GetHashCode() {
-          int hash = 0;
+          int hash = 17;
           if (Key != 0) hash ^= Key.GetHashCode();
           if (Value.Length != 0) hash ^= Value.GetHashCode();
           return hash;
@@ -2285,6 +2288,7 @@ namespace Google.Protobuf.TestProtos {
           }
           return size;
         }
+
         public void MergeFrom(MapInt32ToBytesEntry other) {
           if (other == null) {
             return;
@@ -2395,7 +2399,7 @@ namespace Google.Protobuf.TestProtos {
         }
 
         public override int GetHashCode() {
-          int hash = 0;
+          int hash = 17;
           if (Key != false) hash ^= Key.GetHashCode();
           if (Value != global::Google.Protobuf.TestProtos.TestAllTypes.Types.NestedEnum.NESTED_ENUM_UNSPECIFIED) hash ^= Value.GetHashCode();
           return hash;
@@ -2422,6 +2426,7 @@ namespace Google.Protobuf.TestProtos {
           }
           return size;
         }
+
         public void MergeFrom(MapBoolToEnumEntry other) {
           if (other == null) {
             return;
@@ -2548,7 +2553,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (child_ != null) hash ^= Child.GetHashCode();
       if (payload_ != null) hash ^= Payload.GetHashCode();
       hash ^= repeatedChild_.GetHashCode();
@@ -2585,6 +2590,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(NestedTestAllTypes other) {
       if (other == null) {
         return;
@@ -2701,7 +2707,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (DeprecatedInt32 != 0) hash ^= DeprecatedInt32.GetHashCode();
       return hash;
     }
@@ -2720,6 +2726,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(TestDeprecatedFields other) {
       if (other == null) {
         return;
@@ -2811,7 +2818,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (C != 0) hash ^= C.GetHashCode();
       return hash;
     }
@@ -2830,6 +2837,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(ForeignMessage other) {
       if (other == null) {
         return;
@@ -2909,7 +2917,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       return hash;
     }
 
@@ -2920,6 +2928,7 @@ namespace Google.Protobuf.TestProtos {
       int size = 0;
       return size;
     }
+
     public void MergeFrom(TestReservedFields other) {
       if (other == null) {
         return;
@@ -3005,7 +3014,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (foreignNested_ != null) hash ^= ForeignNested.GetHashCode();
       return hash;
     }
@@ -3024,6 +3033,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(TestForeignNested other) {
       if (other == null) {
         return;
@@ -3133,7 +3143,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (A != 0) hash ^= A.GetHashCode();
       if (Bb != 0) hash ^= Bb.GetHashCode();
       return hash;
@@ -3160,6 +3170,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(TestReallyLargeTagNumber other) {
       if (other == null) {
         return;
@@ -3271,7 +3282,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (a_ != null) hash ^= A.GetHashCode();
       if (I != 0) hash ^= I.GetHashCode();
       return hash;
@@ -3298,6 +3309,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(TestRecursiveMessage other) {
       if (other == null) {
         return;
@@ -3403,7 +3415,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (bb_ != null) hash ^= Bb.GetHashCode();
       return hash;
     }
@@ -3422,6 +3434,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(TestMutualRecursionA other) {
       if (other == null) {
         return;
@@ -3532,7 +3545,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (a_ != null) hash ^= A.GetHashCode();
       if (OptionalInt32 != 0) hash ^= OptionalInt32.GetHashCode();
       return hash;
@@ -3559,6 +3572,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(TestMutualRecursionB other) {
       if (other == null) {
         return;
@@ -3736,7 +3750,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (PrimitiveField != 0) hash ^= PrimitiveField.GetHashCode();
       if (StringField.Length != 0) hash ^= StringField.GetHashCode();
       if (EnumField != global::Google.Protobuf.TestProtos.ForeignEnum.FOREIGN_UNSPECIFIED) hash ^= EnumField.GetHashCode();
@@ -3827,6 +3841,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(TestCamelCaseFieldNames other) {
       if (other == null) {
         return;
@@ -4004,7 +4019,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (MyString.Length != 0) hash ^= MyString.GetHashCode();
       if (MyInt != 0L) hash ^= MyInt.GetHashCode();
       if (MyFloat != 0F) hash ^= MyFloat.GetHashCode();
@@ -4047,6 +4062,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(TestFieldOrderings other) {
       if (other == null) {
         return;
@@ -4178,7 +4194,7 @@ namespace Google.Protobuf.TestProtos {
         }
 
         public override int GetHashCode() {
-          int hash = 0;
+          int hash = 17;
           if (Oo != 0L) hash ^= Oo.GetHashCode();
           if (Bb != 0) hash ^= Bb.GetHashCode();
           return hash;
@@ -4205,6 +4221,7 @@ namespace Google.Protobuf.TestProtos {
           }
           return size;
         }
+
         public void MergeFrom(NestedMessage other) {
           if (other == null) {
             return;
@@ -4308,7 +4325,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (SparseEnum != global::Google.Protobuf.TestProtos.TestSparseEnum.TEST_SPARSE_ENUM_UNSPECIFIED) hash ^= SparseEnum.GetHashCode();
       return hash;
     }
@@ -4327,6 +4344,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(SparseEnumMessage other) {
       if (other == null) {
         return;
@@ -4418,7 +4436,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Data.Length != 0) hash ^= Data.GetHashCode();
       return hash;
     }
@@ -4437,6 +4455,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(OneString other) {
       if (other == null) {
         return;
@@ -4525,7 +4544,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       hash ^= data_.GetHashCode();
       return hash;
     }
@@ -4548,6 +4567,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(MoreString other) {
       if (other == null) {
         return;
@@ -4637,7 +4657,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Data.Length != 0) hash ^= Data.GetHashCode();
       return hash;
     }
@@ -4656,6 +4676,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(OneBytes other) {
       if (other == null) {
         return;
@@ -4747,7 +4768,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Data.Length != 0) hash ^= Data.GetHashCode();
       return hash;
     }
@@ -4766,6 +4787,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(MoreBytes other) {
       if (other == null) {
         return;
@@ -4857,7 +4879,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Data != 0) hash ^= Data.GetHashCode();
       return hash;
     }
@@ -4876,6 +4898,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(Int32Message other) {
       if (other == null) {
         return;
@@ -4967,7 +4990,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Data != 0) hash ^= Data.GetHashCode();
       return hash;
     }
@@ -4986,6 +5009,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(Uint32Message other) {
       if (other == null) {
         return;
@@ -5077,7 +5101,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Data != 0L) hash ^= Data.GetHashCode();
       return hash;
     }
@@ -5096,6 +5120,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(Int64Message other) {
       if (other == null) {
         return;
@@ -5187,7 +5212,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Data != 0UL) hash ^= Data.GetHashCode();
       return hash;
     }
@@ -5206,6 +5231,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(Uint64Message other) {
       if (other == null) {
         return;
@@ -5297,7 +5323,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Data != false) hash ^= Data.GetHashCode();
       return hash;
     }
@@ -5316,6 +5342,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(BoolMessage other) {
       if (other == null) {
         return;
@@ -5459,7 +5486,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (fooCase_ == FooOneofCase.FooInt) hash ^= FooInt.GetHashCode();
       if (fooCase_ == FooOneofCase.FooString) hash ^= FooString.GetHashCode();
       if (fooCase_ == FooOneofCase.FooMessage) hash ^= FooMessage.GetHashCode();
@@ -5494,6 +5521,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(TestOneof other) {
       if (other == null) {
         return;
@@ -5721,7 +5749,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       hash ^= packedInt32_.GetHashCode();
       hash ^= packedInt64_.GetHashCode();
       hash ^= packedUint32_.GetHashCode();
@@ -5900,6 +5928,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(TestPackedTypes other) {
       if (other == null) {
         return;
@@ -6182,7 +6211,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       hash ^= unpackedInt32_.GetHashCode();
       hash ^= unpackedInt64_.GetHashCode();
       hash ^= unpackedUint32_.GetHashCode();
@@ -6347,6 +6376,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(TestUnpackedTypes other) {
       if (other == null) {
         return;
@@ -6557,7 +6587,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       hash ^= repeatedFixed32_.GetHashCode();
       hash ^= repeatedInt32_.GetHashCode();
       hash ^= repeatedFixed64_.GetHashCode();
@@ -6640,6 +6670,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(TestRepeatedScalarDifferentTagSizes other) {
       if (other == null) {
         return;
@@ -6760,7 +6791,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (A.Length != 0) hash ^= A.GetHashCode();
       return hash;
     }
@@ -6779,6 +6810,7 @@ namespace Google.Protobuf.TestProtos {
       }
       return size;
     }
+
     public void MergeFrom(TestCommentInjectionMessage other) {
       if (other == null) {
         return;
@@ -6858,7 +6890,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       return hash;
     }
 
@@ -6869,6 +6901,7 @@ namespace Google.Protobuf.TestProtos {
       int size = 0;
       return size;
     }
+
     public void MergeFrom(FooRequest other) {
       if (other == null) {
         return;
@@ -6941,7 +6974,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       return hash;
     }
 
@@ -6952,6 +6985,7 @@ namespace Google.Protobuf.TestProtos {
       int size = 0;
       return size;
     }
+
     public void MergeFrom(FooResponse other) {
       if (other == null) {
         return;
@@ -7024,7 +7058,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       return hash;
     }
 
@@ -7035,6 +7069,7 @@ namespace Google.Protobuf.TestProtos {
       int size = 0;
       return size;
     }
+
     public void MergeFrom(FooClientMessage other) {
       if (other == null) {
         return;
@@ -7107,7 +7142,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       return hash;
     }
 
@@ -7118,6 +7153,7 @@ namespace Google.Protobuf.TestProtos {
       int size = 0;
       return size;
     }
+
     public void MergeFrom(FooServerMessage other) {
       if (other == null) {
         return;
@@ -7190,7 +7226,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       return hash;
     }
 
@@ -7201,6 +7237,7 @@ namespace Google.Protobuf.TestProtos {
       int size = 0;
       return size;
     }
+
     public void MergeFrom(BarRequest other) {
       if (other == null) {
         return;
@@ -7273,7 +7310,7 @@ namespace Google.Protobuf.TestProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       return hash;
     }
 
@@ -7284,6 +7321,7 @@ namespace Google.Protobuf.TestProtos {
       int size = 0;
       return size;
     }
+
     public void MergeFrom(BarResponse other) {
       if (other == null) {
         return;
diff --git a/csharp/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs b/csharp/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs
index eedb21fe3..d1156fecf 100644
--- a/csharp/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs
+++ b/csharp/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs
@@ -335,7 +335,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       hash ^= file_.GetHashCode();
       return hash;
     }
@@ -356,6 +356,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(FileDescriptorSet other) {
       if (other == null) {
         return;
@@ -558,7 +559,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
       if (Package.Length != 0) hash ^= Package.GetHashCode();
       hash ^= dependency_.GetHashCode();
@@ -685,6 +686,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(FileDescriptorProto other) {
       if (other == null) {
         return;
@@ -938,7 +940,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
       hash ^= field_.GetHashCode();
       hash ^= extension_.GetHashCode();
@@ -1047,6 +1049,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(DescriptorProto other) {
       if (other == null) {
         return;
@@ -1204,7 +1207,7 @@ namespace Google.Protobuf.DescriptorProtos {
         }
 
         public override int GetHashCode() {
-          int hash = 0;
+          int hash = 17;
           if (Start != 0) hash ^= Start.GetHashCode();
           if (End != 0) hash ^= End.GetHashCode();
           return hash;
@@ -1231,6 +1234,7 @@ namespace Google.Protobuf.DescriptorProtos {
           }
           return size;
         }
+
         public void MergeFrom(ExtensionRange other) {
           if (other == null) {
             return;
@@ -1341,7 +1345,7 @@ namespace Google.Protobuf.DescriptorProtos {
         }
 
         public override int GetHashCode() {
-          int hash = 0;
+          int hash = 17;
           if (Start != 0) hash ^= Start.GetHashCode();
           if (End != 0) hash ^= End.GetHashCode();
           return hash;
@@ -1368,6 +1372,7 @@ namespace Google.Protobuf.DescriptorProtos {
           }
           return size;
         }
+
         public void MergeFrom(ReservedRange other) {
           if (other == null) {
             return;
@@ -1568,7 +1573,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
       if (Number != 0) hash ^= Number.GetHashCode();
       if (Label != global::Google.Protobuf.DescriptorProtos.FieldDescriptorProto.Types.Label.LABEL_OPTIONAL) hash ^= Label.GetHashCode();
@@ -1651,6 +1656,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(FieldDescriptorProto other) {
       if (other == null) {
         return;
@@ -1837,7 +1843,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
       return hash;
     }
@@ -1856,6 +1862,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(OneofDescriptorProto other) {
       if (other == null) {
         return;
@@ -1969,7 +1976,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
       hash ^= value_.GetHashCode();
       if (options_ != null) hash ^= Options.GetHashCode();
@@ -2006,6 +2013,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(EnumDescriptorProto other) {
       if (other == null) {
         return;
@@ -2140,7 +2148,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
       if (Number != 0) hash ^= Number.GetHashCode();
       if (options_ != null) hash ^= Options.GetHashCode();
@@ -2175,6 +2183,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(EnumValueDescriptorProto other) {
       if (other == null) {
         return;
@@ -2308,7 +2317,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
       hash ^= method_.GetHashCode();
       if (options_ != null) hash ^= Options.GetHashCode();
@@ -2345,6 +2354,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(ServiceDescriptorProto other) {
       if (other == null) {
         return;
@@ -2515,7 +2525,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Name.Length != 0) hash ^= Name.GetHashCode();
       if (InputType.Length != 0) hash ^= InputType.GetHashCode();
       if (OutputType.Length != 0) hash ^= OutputType.GetHashCode();
@@ -2574,6 +2584,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(MethodDescriptorProto other) {
       if (other == null) {
         return;
@@ -2871,7 +2882,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (JavaPackage.Length != 0) hash ^= JavaPackage.GetHashCode();
       if (JavaOuterClassname.Length != 0) hash ^= JavaOuterClassname.GetHashCode();
       if (JavaMultipleFiles != false) hash ^= JavaMultipleFiles.GetHashCode();
@@ -3004,6 +3015,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(FileOptions other) {
       if (other == null) {
         return;
@@ -3248,7 +3260,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (MessageSetWireFormat != false) hash ^= MessageSetWireFormat.GetHashCode();
       if (NoStandardDescriptorAccessor != false) hash ^= NoStandardDescriptorAccessor.GetHashCode();
       if (Deprecated != false) hash ^= Deprecated.GetHashCode();
@@ -3301,6 +3313,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(MessageOptions other) {
       if (other == null) {
         return;
@@ -3487,7 +3500,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Ctype != global::Google.Protobuf.DescriptorProtos.FieldOptions.Types.CType.STRING) hash ^= Ctype.GetHashCode();
       if (Packed != false) hash ^= Packed.GetHashCode();
       if (Jstype != global::Google.Protobuf.DescriptorProtos.FieldOptions.Types.JSType.JS_NORMAL) hash ^= Jstype.GetHashCode();
@@ -3556,6 +3569,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(FieldOptions other) {
       if (other == null) {
         return;
@@ -3726,7 +3740,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (AllowAlias != false) hash ^= AllowAlias.GetHashCode();
       if (Deprecated != false) hash ^= Deprecated.GetHashCode();
       hash ^= uninterpretedOption_.GetHashCode();
@@ -3763,6 +3777,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(EnumOptions other) {
       if (other == null) {
         return;
@@ -3875,7 +3890,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Deprecated != false) hash ^= Deprecated.GetHashCode();
       hash ^= uninterpretedOption_.GetHashCode();
       return hash;
@@ -3904,6 +3919,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(EnumValueOptions other) {
       if (other == null) {
         return;
@@ -4009,7 +4025,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Deprecated != false) hash ^= Deprecated.GetHashCode();
       hash ^= uninterpretedOption_.GetHashCode();
       return hash;
@@ -4038,6 +4054,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(ServiceOptions other) {
       if (other == null) {
         return;
@@ -4143,7 +4160,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       if (Deprecated != false) hash ^= Deprecated.GetHashCode();
       hash ^= uninterpretedOption_.GetHashCode();
       return hash;
@@ -4172,6 +4189,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(MethodOptions other) {
       if (other == null) {
         return;
@@ -4337,7 +4355,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       hash ^= name_.GetHashCode();
       if (IdentifierValue.Length != 0) hash ^= IdentifierValue.GetHashCode();
       if (PositiveIntValue != 0UL) hash ^= PositiveIntValue.GetHashCode();
@@ -4406,6 +4424,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(UninterpretedOption other) {
       if (other == null) {
         return;
@@ -4550,7 +4569,7 @@ namespace Google.Protobuf.DescriptorProtos {
         }
 
         public override int GetHashCode() {
-          int hash = 0;
+          int hash = 17;
           if (NamePart_.Length != 0) hash ^= NamePart_.GetHashCode();
           if (IsExtension != false) hash ^= IsExtension.GetHashCode();
           return hash;
@@ -4577,6 +4596,7 @@ namespace Google.Protobuf.DescriptorProtos {
           }
           return size;
         }
+
         public void MergeFrom(NamePart other) {
           if (other == null) {
             return;
@@ -4677,7 +4697,7 @@ namespace Google.Protobuf.DescriptorProtos {
     }
 
     public override int GetHashCode() {
-      int hash = 0;
+      int hash = 17;
       hash ^= location_.GetHashCode();
       return hash;
     }
@@ -4698,6 +4718,7 @@ namespace Google.Protobuf.DescriptorProtos {
       }
       return size;
     }
+
     public void MergeFrom(SourceCodeInfo other) {
       if (other == null) {
         return;
@@ -4827,7 +4848,7 @@ namespace Google.Protobuf.DescriptorProtos {
         }
 
         public override int GetHashCode() {
-          int hash = 0;
+          int hash = 17;
           hash ^= path_.GetHashCode();
           hash ^= span_.GetHashCode();
           if (LeadingComments.Length != 0) hash ^= LeadingComments.GetHashCode();
@@ -4892,6 +4913,7 @@ namespace Google.Protobuf.DescriptorProtos {
           }
           return size;
         }
+
         public void MergeFrom(Location other) {
           if (other == null) {
             return;