diff --git a/src/wasm/module-decoder.cc b/src/wasm/module-decoder.cc
index 829e5d4aca..a0ee912174 100644
--- a/src/wasm/module-decoder.cc
+++ b/src/wasm/module-decoder.cc
@@ -238,7 +238,8 @@ class ModuleDecoder : public Decoder {
     pos = pc_;
     {
       uint32_t magic_version = consume_u32("wasm version");
-      if (magic_version != kWasmVersion) {
+      if (magic_version != kWasmVersion &&
+          magic_version != kWasmLegacyVersion) {
         error(pos, pos,
               "expected version %02x %02x %02x %02x, "
               "found %02x %02x %02x %02x",
diff --git a/src/wasm/wasm-module.h b/src/wasm/wasm-module.h
index 36f03590b3..ffb02bb8f4 100644
--- a/src/wasm/wasm-module.h
+++ b/src/wasm/wasm-module.h
@@ -35,7 +35,9 @@ namespace wasm {
 class ErrorThrower;
 
 const uint32_t kWasmMagic = 0x6d736100;
-const uint32_t kWasmVersion = 0x0d;
+const uint32_t kWasmVersion = 0x01;
+// Legacy version supported for short transitionary period.
+const uint32_t kWasmLegacyVersion = 0x0d;
 
 const uint8_t kWasmFunctionTypeForm = 0x60;
 const uint8_t kWasmAnyFunctionTypeForm = 0x70;
diff --git a/test/inspector/debugger/wasm-get-breakable-locations-expected.txt b/test/inspector/debugger/wasm-get-breakable-locations-expected.txt
index aed75bfc85..736117bf97 100644
--- a/test/inspector/debugger/wasm-get-breakable-locations-expected.txt
+++ b/test/inspector/debugger/wasm-get-breakable-locations-expected.txt
@@ -1,9 +1,9 @@
 Running testFunction...
 Script nr 0 parsed. URL: v8://test/setup
 Script nr 1 parsed. URL: v8://test/runTestFunction
-Script nr 2 parsed. URL: wasm://wasm/wasm-824d794e/wasm-824d794e-0
+Script nr 2 parsed. URL: wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-0
 This is a wasm script (nr 0).
-Script nr 3 parsed. URL: wasm://wasm/wasm-824d794e/wasm-824d794e-1
+Script nr 3 parsed. URL: wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-1
 This is a wasm script (nr 1).
 Querying breakable locations for all wasm scripts now...
 Requesting all breakable locations in wasm script 0
@@ -37,51 +37,51 @@ Requesting breakable locations in lines [4,6)
 [0] 4:6 ||       >call 0
 [1] 5:4 ||     >end
 Setting a breakpoint on each breakable location...
-Setting at wasm://wasm/wasm-824d794e/wasm-824d794e-0:2:2
+Setting at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-0:2:2
 Success!
-Setting at wasm://wasm/wasm-824d794e/wasm-824d794e-0:3:2
+Setting at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-0:3:2
 Success!
-Setting at wasm://wasm/wasm-824d794e/wasm-824d794e-0:4:2
+Setting at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-0:4:2
 Success!
-Setting at wasm://wasm/wasm-824d794e/wasm-824d794e-0:5:0
+Setting at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-0:5:0
 Success!
-Setting at wasm://wasm/wasm-824d794e/wasm-824d794e-1:1:2
+Setting at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-1:1:2
 Success!
-Setting at wasm://wasm/wasm-824d794e/wasm-824d794e-1:2:2
+Setting at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-1:2:2
 Success!
-Setting at wasm://wasm/wasm-824d794e/wasm-824d794e-1:3:4
+Setting at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-1:3:4
 Success!
-Setting at wasm://wasm/wasm-824d794e/wasm-824d794e-1:4:6
+Setting at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-1:4:6
 Success!
-Setting at wasm://wasm/wasm-824d794e/wasm-824d794e-1:5:4
+Setting at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-1:5:4
 Success!
-Setting at wasm://wasm/wasm-824d794e/wasm-824d794e-1:6:2
+Setting at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-1:6:2
 Success!
-Setting at wasm://wasm/wasm-824d794e/wasm-824d794e-1:7:0
+Setting at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-1:7:0
 Success!
 Running wasm code...
 Missing breakpoints: 11
 Script nr 4 parsed. URL: v8://test/runWasm
-Stopped at wasm://wasm/wasm-824d794e/wasm-824d794e-1:1:2
+Stopped at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-1:1:2
 Missing breakpoints: 10
-Stopped at wasm://wasm/wasm-824d794e/wasm-824d794e-1:2:2
+Stopped at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-1:2:2
 Missing breakpoints: 9
-Stopped at wasm://wasm/wasm-824d794e/wasm-824d794e-1:3:4
+Stopped at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-1:3:4
 Missing breakpoints: 8
-Stopped at wasm://wasm/wasm-824d794e/wasm-824d794e-1:4:6
+Stopped at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-1:4:6
 Missing breakpoints: 7
-Stopped at wasm://wasm/wasm-824d794e/wasm-824d794e-0:2:2
+Stopped at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-0:2:2
 Missing breakpoints: 6
-Stopped at wasm://wasm/wasm-824d794e/wasm-824d794e-0:3:2
+Stopped at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-0:3:2
 Missing breakpoints: 5
-Stopped at wasm://wasm/wasm-824d794e/wasm-824d794e-0:4:2
+Stopped at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-0:4:2
 Missing breakpoints: 4
-Stopped at wasm://wasm/wasm-824d794e/wasm-824d794e-0:5:0
+Stopped at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-0:5:0
 Missing breakpoints: 3
-Stopped at wasm://wasm/wasm-824d794e/wasm-824d794e-1:5:4
+Stopped at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-1:5:4
 Missing breakpoints: 2
-Stopped at wasm://wasm/wasm-824d794e/wasm-824d794e-1:6:2
+Stopped at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-1:6:2
 Missing breakpoints: 1
-Stopped at wasm://wasm/wasm-824d794e/wasm-824d794e-1:7:0
+Stopped at wasm://wasm/wasm-eb3c2032/wasm-eb3c2032-1:7:0
 Missing breakpoints: 0
 Finished!
diff --git a/test/inspector/debugger/wasm-scripts-expected.txt b/test/inspector/debugger/wasm-scripts-expected.txt
index 284cc05571..040d125ec7 100644
--- a/test/inspector/debugger/wasm-scripts-expected.txt
+++ b/test/inspector/debugger/wasm-scripts-expected.txt
@@ -1,14 +1,14 @@
 Check that inspector gets two wasm scripts at module creation time.
 Script #0 parsed. URL: v8://test/testFunction
 Script #1 parsed. URL: v8://test/runTestRunction
-Script #2 parsed. URL: wasm://wasm/wasm-e783515e/wasm-e783515e-0
-Script #3 parsed. URL: wasm://wasm/wasm-e783515e/wasm-e783515e-1
-Source for wasm://wasm/wasm-e783515e/wasm-e783515e-0:
+Script #2 parsed. URL: wasm://wasm/wasm-4205e2ce/wasm-4205e2ce-0
+Script #3 parsed. URL: wasm://wasm/wasm-4205e2ce/wasm-4205e2ce-1
+Source for wasm://wasm/wasm-4205e2ce/wasm-4205e2ce-0:
 func $nopFunction
   nop
 end
 
-Source for wasm://wasm/wasm-e783515e/wasm-e783515e-1:
+Source for wasm://wasm/wasm-4205e2ce/wasm-4205e2ce-1:
 func $main
   block
     i32.const 2
diff --git a/test/inspector/debugger/wasm-stepping-expected.txt b/test/inspector/debugger/wasm-stepping-expected.txt
index f341053d53..922d51aa49 100644
--- a/test/inspector/debugger/wasm-stepping-expected.txt
+++ b/test/inspector/debugger/wasm-stepping-expected.txt
@@ -2,10 +2,10 @@ Installing code an global variable.
 Calling instantiate function.
 Waiting for two wasm scripts to be parsed.
 Ignoring script with url v8://test/callInstantiate
-Got wasm script: wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-0
-Requesting source for wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-0...
-Got wasm script: wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1
-Requesting source for wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1...
+Got wasm script: wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-0
+Requesting source for wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-0...
+Got wasm script: wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1
+Requesting source for wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1...
 func $wasm_A
   nop
   nop
@@ -25,59 +25,59 @@ func $wasm_B (param i32)
   end
 end
 
-Setting breakpoint on line 7 (on the setlocal before the call), url wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1
+Setting breakpoint on line 7 (on the setlocal before the call), url wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1
 {
     columnNumber : 6
     lineNumber : 7
     scriptId : <scriptId>
 }
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:7:6:       >set_local 0
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:7:6:       >set_local 0
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:8:6:       >call 0
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:8:6:       >call 0
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-0:1:2:   >nop
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-0:1:2:   >nop
 Step action: stepOver
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-0:2:2:   >nop
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-0:2:2:   >nop
 Step action: stepOut
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:9:6:       >br 1
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:9:6:       >br 1
 Step action: stepOut
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:7:6:       >set_local 0
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:7:6:       >set_local 0
 Step action: stepOver
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:8:6:       >call 0
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:8:6:       >call 0
 Step action: stepOver
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:9:6:       >br 1
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:9:6:       >br 1
 Step action: resume
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:7:6:       >set_local 0
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:7:6:       >set_local 0
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:8:6:       >call 0
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:8:6:       >call 0
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-0:1:2:   >nop
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-0:1:2:   >nop
 Step action: stepOut
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:9:6:       >br 1
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:9:6:       >br 1
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:1:2:   >loop
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:1:2:   >loop
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:2:4:     >get_local 0
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:2:4:     >get_local 0
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:3:4:     >if
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:3:4:     >if
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:4:6:       >get_local 0
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:4:6:       >get_local 0
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:5:6:       >i32.const 1
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:5:6:       >i32.const 1
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:6:6:       >i32.sub
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:6:6:       >i32.sub
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:7:6:       >set_local 0
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:7:6:       >set_local 0
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:8:6:       >call 0
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:8:6:       >call 0
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-0:1:2:   >nop
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-0:1:2:   >nop
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-0:2:2:   >nop
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-0:2:2:   >nop
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-0:3:0: >end
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-0:3:0: >end
 Step action: stepInto
-Paused at wasm://wasm/wasm-ccfaf3fa/wasm-ccfaf3fa-1:9:6:       >br 1
+Paused at wasm://wasm/wasm-0e9ccf72/wasm-0e9ccf72-1:9:6:       >br 1
 Step action: resume
 exports.main returned!
 Finished!
diff --git a/test/mjsunit/wasm/incrementer.wasm b/test/mjsunit/wasm/incrementer.wasm
index eba6007730..47afcdef2a 100644
Binary files a/test/mjsunit/wasm/incrementer.wasm and b/test/mjsunit/wasm/incrementer.wasm differ
diff --git a/test/mjsunit/wasm/wasm-constants.js b/test/mjsunit/wasm/wasm-constants.js
index d3a8a2e9af..e677f538d7 100644
--- a/test/mjsunit/wasm/wasm-constants.js
+++ b/test/mjsunit/wasm/wasm-constants.js
@@ -21,7 +21,7 @@ var kWasmH1 = 0x61;
 var kWasmH2 = 0x73;
 var kWasmH3 = 0x6d;
 
-var kWasmV0 = 0xD;
+var kWasmV0 = 0x1;
 var kWasmV1 = 0;
 var kWasmV2 = 0;
 var kWasmV3 = 0;
diff --git a/test/unittests/value-serializer-unittest.cc b/test/unittests/value-serializer-unittest.cc
index 06d93a53c8..816caddd80 100644
--- a/test/unittests/value-serializer-unittest.cc
+++ b/test/unittests/value-serializer-unittest.cc
@@ -2556,9 +2556,9 @@ bool ValueSerializerTestWithWasm::g_saved_flag = false;
 // A simple module which exports an "increment" function.
 // Copied from test/mjsunit/wasm/incrementer.wasm.
 const unsigned char kIncrementerWasm[] = {
-    0,   97, 115, 109, 13, 0,  0, 0, 1,   6,   1,  96,  1,   127, 1,   127,
-    3,   2,  1,   0,   7,  13, 1, 9, 105, 110, 99, 114, 101, 109, 101, 110,
-    116, 0,  0,   10,  9,  1,  7, 0, 32,  0,   65, 1,   106, 11,
+    0,   97, 115, 109, 1, 0,  0, 0, 1,   6,   1,  96,  1,   127, 1,   127,
+    3,   2,  1,   0,   7, 13, 1, 9, 105, 110, 99, 114, 101, 109, 101, 110,
+    116, 0,  0,   10,  9, 1,  7, 0, 32,  0,   65, 1,   106, 11,
 };
 
 TEST_F(ValueSerializerTestWithWasm, RoundTripWasmModule) {