diff --git a/src/code-stub-assembler.cc b/src/code-stub-assembler.cc
index cdd36b30d1..4f2d5ad8ae 100644
--- a/src/code-stub-assembler.cc
+++ b/src/code-stub-assembler.cc
@@ -1956,8 +1956,8 @@ Node* CodeStubAssembler::OrdinaryHasInstance(Node* context, Node* callable,
 
     // Check the current {object} prototype.
     Node* object_prototype = LoadMapPrototype(object_map);
-    GotoIf(WordEqual(object_prototype, callable_prototype), &return_true);
     GotoIf(WordEqual(object_prototype, NullConstant()), &return_false);
+    GotoIf(WordEqual(object_prototype, callable_prototype), &return_true);
 
     // Continue with the prototype.
     var_object_map.Bind(LoadMap(object_prototype));
diff --git a/src/compiler/js-typed-lowering.cc b/src/compiler/js-typed-lowering.cc
index faf1251f7d..32316bf323 100644
--- a/src/compiler/js-typed-lowering.cc
+++ b/src/compiler/js-typed-lowering.cc
@@ -1267,6 +1267,17 @@ Reduction JSTypedLowering::ReduceJSInstanceOf(Node* node) {
       simplified()->LoadField(AccessBuilder::ForMapPrototype()),
       loop_object_map, loop_effect, control);
 
+  // If not, check if object prototype is the null prototype.
+  Node* null_proto =
+      graph()->NewNode(simplified()->ReferenceEqual(r.right_type()),
+                       object_prototype, jsgraph()->NullConstant());
+  Node* branch_null_proto = graph()->NewNode(
+      common()->Branch(BranchHint::kFalse), null_proto, control);
+  Node* if_null_proto = graph()->NewNode(common()->IfTrue(), branch_null_proto);
+  Node* e_null_proto = effect;
+
+  control = graph()->NewNode(common()->IfFalse(), branch_null_proto);
+
   // Check if object prototype is equal to function prototype.
   Node* eq_proto =
       graph()->NewNode(simplified()->ReferenceEqual(r.right_type()),
@@ -1278,16 +1289,6 @@ Reduction JSTypedLowering::ReduceJSInstanceOf(Node* node) {
 
   control = graph()->NewNode(common()->IfFalse(), branch_eq_proto);
 
-  // If not, check if object prototype is the null prototype.
-  Node* null_proto =
-      graph()->NewNode(simplified()->ReferenceEqual(r.right_type()),
-                       object_prototype, jsgraph()->NullConstant());
-  Node* branch_null_proto = graph()->NewNode(
-      common()->Branch(BranchHint::kFalse), null_proto, control);
-  Node* if_null_proto = graph()->NewNode(common()->IfTrue(), branch_null_proto);
-  Node* e_null_proto = effect;
-
-  control = graph()->NewNode(common()->IfFalse(), branch_null_proto);
   Node* load_object_map = effect =
       graph()->NewNode(simplified()->LoadField(AccessBuilder::ForMap()),
                        object_prototype, effect, control);
diff --git a/src/crankshaft/arm/lithium-codegen-arm.cc b/src/crankshaft/arm/lithium-codegen-arm.cc
index 92ba70e587..4fd039554c 100644
--- a/src/crankshaft/arm/lithium-codegen-arm.cc
+++ b/src/crankshaft/arm/lithium-codegen-arm.cc
@@ -2525,10 +2525,10 @@ void LCodeGen::DoHasInPrototypeChainAndBranch(
   DeoptimizeIf(eq, instr, Deoptimizer::kProxy);
 
   __ ldr(object_prototype, FieldMemOperand(object_map, Map::kPrototypeOffset));
-  __ cmp(object_prototype, prototype);
-  EmitTrueBranch(instr, eq);
   __ CompareRoot(object_prototype, Heap::kNullValueRootIndex);
   EmitFalseBranch(instr, eq);
+  __ cmp(object_prototype, prototype);
+  EmitTrueBranch(instr, eq);
   __ ldr(object_map, FieldMemOperand(object_prototype, HeapObject::kMapOffset));
   __ b(&loop);
 }
diff --git a/src/crankshaft/arm64/lithium-codegen-arm64.cc b/src/crankshaft/arm64/lithium-codegen-arm64.cc
index d939341466..5e6b905af0 100644
--- a/src/crankshaft/arm64/lithium-codegen-arm64.cc
+++ b/src/crankshaft/arm64/lithium-codegen-arm64.cc
@@ -2832,10 +2832,10 @@ void LCodeGen::DoHasInPrototypeChainAndBranch(
   DeoptimizeIf(eq, instr, Deoptimizer::kProxy);
 
   __ Ldr(object_prototype, FieldMemOperand(object_map, Map::kPrototypeOffset));
-  __ Cmp(object_prototype, prototype);
-  __ B(eq, instr->TrueLabel(chunk_));
   __ CompareRoot(object_prototype, Heap::kNullValueRootIndex);
   __ B(eq, instr->FalseLabel(chunk_));
+  __ Cmp(object_prototype, prototype);
+  __ B(eq, instr->TrueLabel(chunk_));
   __ Ldr(object_map, FieldMemOperand(object_prototype, HeapObject::kMapOffset));
   __ B(&loop);
 }
diff --git a/src/crankshaft/ia32/lithium-codegen-ia32.cc b/src/crankshaft/ia32/lithium-codegen-ia32.cc
index 203ae9e3b6..ff05c0ae6a 100644
--- a/src/crankshaft/ia32/lithium-codegen-ia32.cc
+++ b/src/crankshaft/ia32/lithium-codegen-ia32.cc
@@ -2316,10 +2316,10 @@ void LCodeGen::DoHasInPrototypeChainAndBranch(
   DeoptimizeIf(equal, instr, Deoptimizer::kProxy);
 
   __ mov(object_prototype, FieldOperand(object_map, Map::kPrototypeOffset));
-  __ cmp(object_prototype, prototype);
-  EmitTrueBranch(instr, equal);
   __ cmp(object_prototype, factory()->null_value());
   EmitFalseBranch(instr, equal);
+  __ cmp(object_prototype, prototype);
+  EmitTrueBranch(instr, equal);
   __ mov(object_map, FieldOperand(object_prototype, HeapObject::kMapOffset));
   __ jmp(&loop);
 }
diff --git a/src/crankshaft/mips/lithium-codegen-mips.cc b/src/crankshaft/mips/lithium-codegen-mips.cc
index c4faf69635..9a194772c6 100644
--- a/src/crankshaft/mips/lithium-codegen-mips.cc
+++ b/src/crankshaft/mips/lithium-codegen-mips.cc
@@ -2415,9 +2415,9 @@ void LCodeGen::DoHasInPrototypeChainAndBranch(
                Operand(JS_PROXY_TYPE));
 
   __ lw(object_prototype, FieldMemOperand(object_map, Map::kPrototypeOffset));
-  EmitTrueBranch(instr, eq, object_prototype, Operand(prototype));
   __ LoadRoot(at, Heap::kNullValueRootIndex);
   EmitFalseBranch(instr, eq, object_prototype, Operand(at));
+  EmitTrueBranch(instr, eq, object_prototype, Operand(prototype));
   __ Branch(USE_DELAY_SLOT, &loop);
   __ lw(object_map, FieldMemOperand(object_prototype, HeapObject::kMapOffset));
 }
diff --git a/src/crankshaft/mips64/lithium-codegen-mips64.cc b/src/crankshaft/mips64/lithium-codegen-mips64.cc
index 12daa1031e..8c7f1dc641 100644
--- a/src/crankshaft/mips64/lithium-codegen-mips64.cc
+++ b/src/crankshaft/mips64/lithium-codegen-mips64.cc
@@ -2535,9 +2535,9 @@ void LCodeGen::DoHasInPrototypeChainAndBranch(
                Operand(JS_PROXY_TYPE));
 
   __ ld(object_prototype, FieldMemOperand(object_map, Map::kPrototypeOffset));
-  EmitTrueBranch(instr, eq, object_prototype, Operand(prototype));
   __ LoadRoot(at, Heap::kNullValueRootIndex);
   EmitFalseBranch(instr, eq, object_prototype, Operand(at));
+  EmitTrueBranch(instr, eq, object_prototype, Operand(prototype));
   __ Branch(&loop, USE_DELAY_SLOT);
   __ ld(object_map, FieldMemOperand(object_prototype,
                                     HeapObject::kMapOffset));  // In delay slot.
diff --git a/src/crankshaft/ppc/lithium-codegen-ppc.cc b/src/crankshaft/ppc/lithium-codegen-ppc.cc
index 3e2fa7f2fa..c7a5cd1c1c 100644
--- a/src/crankshaft/ppc/lithium-codegen-ppc.cc
+++ b/src/crankshaft/ppc/lithium-codegen-ppc.cc
@@ -2589,10 +2589,10 @@ void LCodeGen::DoHasInPrototypeChainAndBranch(
   DeoptimizeIf(eq, instr, Deoptimizer::kProxy);
   __ LoadP(object_prototype,
            FieldMemOperand(object_map, Map::kPrototypeOffset));
-  __ cmp(object_prototype, prototype);
-  EmitTrueBranch(instr, eq);
   __ CompareRoot(object_prototype, Heap::kNullValueRootIndex);
   EmitFalseBranch(instr, eq);
+  __ cmp(object_prototype, prototype);
+  EmitTrueBranch(instr, eq);
   __ LoadP(object_map,
            FieldMemOperand(object_prototype, HeapObject::kMapOffset));
   __ b(&loop);
diff --git a/src/crankshaft/s390/lithium-codegen-s390.cc b/src/crankshaft/s390/lithium-codegen-s390.cc
index e34859334f..c9191e76f3 100644
--- a/src/crankshaft/s390/lithium-codegen-s390.cc
+++ b/src/crankshaft/s390/lithium-codegen-s390.cc
@@ -2567,10 +2567,10 @@ void LCodeGen::DoHasInPrototypeChainAndBranch(
   DeoptimizeIf(eq, instr, Deoptimizer::kProxy);
   __ LoadP(object_prototype,
            FieldMemOperand(object_map, Map::kPrototypeOffset));
-  __ CmpP(object_prototype, prototype);
-  EmitTrueBranch(instr, eq);
   __ CompareRoot(object_prototype, Heap::kNullValueRootIndex);
   EmitFalseBranch(instr, eq);
+  __ CmpP(object_prototype, prototype);
+  EmitTrueBranch(instr, eq);
   __ LoadP(object_map,
            FieldMemOperand(object_prototype, HeapObject::kMapOffset));
   __ b(&loop);
diff --git a/src/crankshaft/x64/lithium-codegen-x64.cc b/src/crankshaft/x64/lithium-codegen-x64.cc
index 16adc2c66c..0746d3b434 100644
--- a/src/crankshaft/x64/lithium-codegen-x64.cc
+++ b/src/crankshaft/x64/lithium-codegen-x64.cc
@@ -2456,7 +2456,6 @@ void LCodeGen::DoHasInPrototypeChainAndBranch(
   Label loop;
   __ bind(&loop);
 
-
   // Deoptimize if the object needs to be access checked.
   __ testb(FieldOperand(object_map, Map::kBitFieldOffset),
            Immediate(1 << Map::kIsAccessCheckNeeded));
@@ -2466,10 +2465,10 @@ void LCodeGen::DoHasInPrototypeChainAndBranch(
   DeoptimizeIf(equal, instr, Deoptimizer::kProxy);
 
   __ movp(object_prototype, FieldOperand(object_map, Map::kPrototypeOffset));
-  __ cmpp(object_prototype, prototype);
-  EmitTrueBranch(instr, equal);
   __ CompareRoot(object_prototype, Heap::kNullValueRootIndex);
   EmitFalseBranch(instr, equal);
+  __ cmpp(object_prototype, prototype);
+  EmitTrueBranch(instr, equal);
   __ movp(object_map, FieldOperand(object_prototype, HeapObject::kMapOffset));
   __ jmp(&loop);
 }
diff --git a/src/crankshaft/x87/lithium-codegen-x87.cc b/src/crankshaft/x87/lithium-codegen-x87.cc
index ccea6958ab..71f68d581e 100644
--- a/src/crankshaft/x87/lithium-codegen-x87.cc
+++ b/src/crankshaft/x87/lithium-codegen-x87.cc
@@ -2602,10 +2602,10 @@ void LCodeGen::DoHasInPrototypeChainAndBranch(
   DeoptimizeIf(equal, instr, Deoptimizer::kProxy);
 
   __ mov(object_prototype, FieldOperand(object_map, Map::kPrototypeOffset));
-  __ cmp(object_prototype, prototype);
-  EmitTrueBranch(instr, equal);
   __ cmp(object_prototype, factory()->null_value());
   EmitFalseBranch(instr, equal);
+  __ cmp(object_prototype, prototype);
+  EmitTrueBranch(instr, equal);
   __ mov(object_map, FieldOperand(object_prototype, HeapObject::kMapOffset));
   __ jmp(&loop);
 }
diff --git a/test/mjsunit/regress/regress-5085.js b/test/mjsunit/regress/regress-5085.js
new file mode 100644
index 0000000000..0ed034dc2d
--- /dev/null
+++ b/test/mjsunit/regress/regress-5085.js
@@ -0,0 +1,14 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+function foo(x) {
+  return x instanceof Proxy;
+}
+
+assertFalse(foo({}));
+assertFalse(foo({}));
+%OptimizeFunctionOnNextCall(foo);
+assertFalse(foo({}));