diff --git a/common.gypi b/common.gypi
index 64e08805c89ad6..0395077e443751 100644
--- a/common.gypi
+++ b/common.gypi
@@ -36,7 +36,7 @@
 
     # Reset this number to 0 on major V8 upgrades.
     # Increment by one for each non-official patch applied to deps/v8.
-    'v8_embedder_string': '-node.49',
+    'v8_embedder_string': '-node.50',
 
     ##### V8 defaults for Node.js #####
 
diff --git a/deps/v8/src/compiler/backend/x64/instruction-selector-x64.cc b/deps/v8/src/compiler/backend/x64/instruction-selector-x64.cc
index dd3f556937d096..56dd17ac693e7e 100644
--- a/deps/v8/src/compiler/backend/x64/instruction-selector-x64.cc
+++ b/deps/v8/src/compiler/backend/x64/instruction-selector-x64.cc
@@ -1270,7 +1270,9 @@ void InstructionSelector::VisitChangeInt32ToInt64(Node* node) {
         opcode = load_rep.IsSigned() ? kX64Movsxwq : kX64Movzxwq;
         break;
       case MachineRepresentation::kWord32:
-        opcode = load_rep.IsSigned() ? kX64Movsxlq : kX64Movl;
+        // ChangeInt32ToInt64 must interpret its input as a _signed_ 32-bit
+        // integer, so here we must sign-extend the loaded value in any case.
+        opcode = kX64Movsxlq;
         break;
       default:
         UNREACHABLE();
diff --git a/deps/v8/test/mjsunit/compiler/regress-1196683.js b/deps/v8/test/mjsunit/compiler/regress-1196683.js
new file mode 100644
index 00000000000000..abd7d6b2f8da45
--- /dev/null
+++ b/deps/v8/test/mjsunit/compiler/regress-1196683.js
@@ -0,0 +1,56 @@
+// Copyright 2021 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() {
+  const arr = new Uint32Array([2**31]);
+  function foo() {
+    return (arr[0] ^ 0) + 1;
+  }
+  %PrepareFunctionForOptimization(foo);
+  assertEquals(-(2**31) + 1, foo());
+  %OptimizeFunctionOnNextCall(foo);
+  assertEquals(-(2**31) + 1, foo());
+});
+
+
+// The remaining tests already passed without the bugfix.
+
+
+(function() {
+  const arr = new Uint16Array([2**15]);
+  function foo() {
+    return (arr[0] ^ 0) + 1;
+  }
+  %PrepareFunctionForOptimization(foo);
+  assertEquals(2**15 + 1, foo());
+  %OptimizeFunctionOnNextCall(foo);
+  assertEquals(2**15 + 1, foo());
+})();
+
+
+(function() {
+  const arr = new Uint8Array([2**7]);
+  function foo() {
+    return (arr[0] ^ 0) + 1;
+  }
+  %PrepareFunctionForOptimization(foo);
+  assertEquals(2**7 + 1, foo());
+  %OptimizeFunctionOnNextCall(foo);
+  assertEquals(2**7 + 1, foo());
+})();
+
+
+(function() {
+  const arr = new Int32Array([-(2**31)]);
+  function foo() {
+    return (arr[0] >>> 0) + 1;
+  }
+  %PrepareFunctionForOptimization(foo);
+  assertEquals(2**31 + 1, foo());
+  %OptimizeFunctionOnNextCall(foo);
+  assertEquals(2**31 + 1, foo());
+})();