diff --git a/include/llbuild/BuildSystem/BuildValue.h b/include/llbuild/BuildSystem/BuildValue.h
index 3867470..148a1b9 100644
--- a/include/llbuild/BuildSystem/BuildValue.h
+++ b/include/llbuild/BuildSystem/BuildValue.h
@@ -100,6 +100,7 @@
   BuildValue() {}
   BuildValue(Kind kind) : kind(kind) {
     valueData.asOutputInfo = {};
+    commandSignature = 0;
   }
   BuildValue(Kind kind, ArrayRef<FileInfo> outputInfos,
              uint64_t commandSignature = 0)
@@ -121,14 +122,16 @@
   // BuildValues can only be moved, not copied.
   BuildValue(BuildValue&& rhs) : numOutputInfos(rhs.numOutputInfos) {
     kind = rhs.kind;
-    if (numOutputInfos == 1) {
-      valueData.asOutputInfo = rhs.valueData.asOutputInfo;
-    } else {
+    numOutputInfos = rhs.numOutputInfos;
+    commandSignature = rhs.commandSignature;
+    if (rhs.hasMultipleOutputs()) {
       valueData.asOutputInfos = rhs.valueData.asOutputInfos;
       rhs.valueData.asOutputInfos = nullptr;
+    } else {
+      valueData.asOutputInfo = rhs.valueData.asOutputInfo;
     }
   }
-  BuildValue &operator=(BuildValue&& rhs) {
+  BuildValue& operator=(BuildValue&& rhs) {
     if (this != &rhs) {
       // Release our resources.
       if (hasMultipleOutputs())
@@ -137,7 +140,8 @@
       // Move the data.
       kind = rhs.kind;
       numOutputInfos = rhs.numOutputInfos;
-      if (numOutputInfos > 1) {
+      commandSignature = rhs.commandSignature;
+      if (rhs.hasMultipleOutputs()) {
         valueData.asOutputInfos = rhs.valueData.asOutputInfos;
         rhs.valueData.asOutputInfos = nullptr;
       } else {
@@ -208,7 +212,9 @@
   bool isFailedInput() const { return kind == Kind::FailedInput; }
   bool isSuccessfulCommand() const {return kind == Kind::SuccessfulCommand; }
   bool isFailedCommand() const { return kind == Kind::FailedCommand; }
-  bool isPropagatedFailureCommand() const { return kind == Kind::PropagatedFailureCommand; }
+  bool isPropagatedFailureCommand() const {
+    return kind == Kind::PropagatedFailureCommand;
+  }
   bool isCancelledCommand() const { return kind == Kind::CancelledCommand; }
   bool isSkippedCommand() const { return kind == Kind::SkippedCommand; }
   bool isTarget() const { return kind == Kind::Target; }
@@ -279,6 +285,9 @@
       std::vector<uint8_t> result(sizeof(*this) +
                                   numOutputInfos * sizeof(FileInfo));
       memcpy(result.data(), this, sizeof(*this));
+      // We must normalize the bytes where the address is stored.
+      memset(result.data() + offsetof(BuildValue, valueData), 0,
+             sizeof(valueData));
       memcpy(result.data() + sizeof(*this), valueData.asOutputInfos,
              numOutputInfos * sizeof(FileInfo));
       return result;
diff --git a/lib/BuildSystem/BuildSystem.cpp b/lib/BuildSystem/BuildSystem.cpp
index ba50b33..154d64e 100644
--- a/lib/BuildSystem/BuildSystem.cpp
+++ b/lib/BuildSystem/BuildSystem.cpp
@@ -128,7 +128,7 @@
 
 class BuildSystemImpl : public BuildSystemCommandInterface {
   /// The internal schema version.
-  static const uint32_t internalSchemaVersion = 3;
+  static const uint32_t internalSchemaVersion = 4;
   
   BuildSystem& buildSystem;
 
diff --git a/llbuild.xcodeproj/project.pbxproj b/llbuild.xcodeproj/project.pbxproj
index 51d0afb..575024a 100644
--- a/llbuild.xcodeproj/project.pbxproj
+++ b/llbuild.xcodeproj/project.pbxproj
@@ -122,6 +122,7 @@
 		E1604CB51BB9E03E001153A1 /* swift-build-tool.cpp in Sources */ = {isa = PBXBuildFile; fileRef = E1604CB41BB9E032001153A1 /* swift-build-tool.cpp */; };
 		E171538D1A0BF702004CD598 /* CorePerfTests.mm in Sources */ = {isa = PBXBuildFile; fileRef = E171538C1A0BF702004CD598 /* CorePerfTests.mm */; };
 		E17440C31CE192FF0070A30C /* ShellUtility.cpp in Sources */ = {isa = PBXBuildFile; fileRef = E17440C21CE192FF0070A30C /* ShellUtility.cpp */; };
+		E192E92F1E30014E00122F17 /* BuildValueTest.cpp in Sources */ = {isa = PBXBuildFile; fileRef = E192E92E1E30014E00122F17 /* BuildValueTest.cpp */; };
 		E19D79921A15D9E6002604FB /* MakefileDepsParser.cpp in Sources */ = {isa = PBXBuildFile; fileRef = E19D79911A15D9E6002604FB /* MakefileDepsParser.cpp */; };
 		E19D79951A15DA06002604FB /* MakefileDepsParserTest.cpp in Sources */ = {isa = PBXBuildFile; fileRef = E19D79941A15DA06002604FB /* MakefileDepsParserTest.cpp */; };
 		E1A0B0FF1C971582006DA08F /* DependencyInfoParser.cpp in Sources */ = {isa = PBXBuildFile; fileRef = E1A0B0FE1C971581006DA08F /* DependencyInfoParser.cpp */; };
@@ -744,6 +745,7 @@
 		E17C29F31B5AC2A700C12DA9 /* build-sphinx-docs.sh */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.script.sh; path = "build-sphinx-docs.sh"; sourceTree = "<group>"; };
 		E18043391A00129400662FE7 /* install-user-lit.sh */ = {isa = PBXFileReference; lastKnownFileType = text.script.sh; path = "install-user-lit.sh"; sourceTree = "<group>"; };
 		E182BE111ABA2B8D001840AD /* Compiler.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = Compiler.h; sourceTree = "<group>"; };
+		E192E92E1E30014E00122F17 /* BuildValueTest.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = BuildValueTest.cpp; sourceTree = "<group>"; };
 		E19C3F171B98B3CB0035E1AA /* extract-perf-data */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; path = "extract-perf-data"; sourceTree = "<group>"; };
 		E19C3F181B98B3CB0035E1AA /* xcs-submit-perf-data.sh */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.script.sh; path = "xcs-submit-perf-data.sh"; sourceTree = "<group>"; };
 		E19C3FD51B98C1A70035E1AA /* tests */ = {isa = PBXFileReference; lastKnownFileType = folder; path = tests; sourceTree = "<group>"; };
@@ -1179,6 +1181,7 @@
 			children = (
 				C5740D0D1E0352D800567DD8 /* CMakeLists.txt */,
 				C5740D081E03523100567DD8 /* BuildSystemFrontendTest.cpp */,
+				E192E92E1E30014E00122F17 /* BuildValueTest.cpp */,
 				9DB0478B1DF9D3E2006CDF52 /* LaneBasedExecutionQueueTest.cpp */,
 				9D0A6D7F1E1FFEA800BE636F /* TempDir.cpp */,
 				9D0A6D801E1FFEA800BE636F /* TempDir.hpp */,
@@ -2608,6 +2611,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				E192E92F1E30014E00122F17 /* BuildValueTest.cpp in Sources */,
 				9DB047C01DF9F592006CDF52 /* LaneBasedExecutionQueueTest.cpp in Sources */,
 				C5740D091E03523100567DD8 /* BuildSystemFrontendTest.cpp in Sources */,
 				9D0A6D811E1FFEA800BE636F /* TempDir.cpp in Sources */,
diff --git a/unittests/BuildSystem/BuildValueTest.cpp b/unittests/BuildSystem/BuildValueTest.cpp
new file mode 100644
index 0000000..4800c93
--- /dev/null
+++ b/unittests/BuildSystem/BuildValueTest.cpp
@@ -0,0 +1,104 @@
+//===- unittests/BuildSystem/BuildValueTest.cpp ---------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2016 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#include "llbuild/BuildSystem/BuildValue.h"
+
+#include "gtest/gtest.h"
+
+using namespace llbuild;
+using namespace llbuild::buildsystem;
+using namespace llvm;
+
+namespace {
+
+TEST(BuildValueTest, virtualValueSerialization) {
+  // Check that two identical values are equivalent.
+  {
+    BuildValue a = BuildValue::makeVirtualInput();
+    EXPECT_EQ(a.toData(), BuildValue::makeVirtualInput().toData());
+  }
+
+  // Check that a moved complex value is equivalent.
+  {
+    BuildValue tmp = BuildValue::makeVirtualInput();
+    BuildValue a = std::move(tmp);
+    EXPECT_EQ(a.toData(), BuildValue::makeVirtualInput().toData());
+  }
+
+  // Check that an rvalue initialized complex value is equivalent.
+  {
+    BuildValue tmp = BuildValue::makeVirtualInput();
+    BuildValue a{ std::move(tmp) };
+    EXPECT_EQ(a.toData(), BuildValue::makeVirtualInput().toData());
+  }
+}
+
+TEST(BuildValueTest, commandValueSingleOutputSerialization) {
+  uint64_t signature = 0xDEADBEEF;
+  basic::FileInfo infos[1] = {};
+  infos[0].size = 1;
+  
+  // Check that two identical values are equivalent.
+  {
+    BuildValue a = BuildValue::makeSuccessfulCommand(infos, signature);
+    EXPECT_EQ(a.toData(),
+              BuildValue::makeSuccessfulCommand(infos, signature).toData());
+  }
+
+  // Check that a moved complex value is equivalent.
+  {
+    BuildValue tmp = BuildValue::makeSuccessfulCommand(infos, signature);
+    BuildValue a = std::move(tmp);
+    EXPECT_EQ(a.toData(),
+              BuildValue::makeSuccessfulCommand(infos, signature).toData());
+  }
+
+  // Check that an rvalue initialized complex value is equivalent.
+  {
+    BuildValue tmp = BuildValue::makeSuccessfulCommand(infos, signature);
+    BuildValue a{ std::move(tmp) };
+    EXPECT_EQ(a.toData(),
+              BuildValue::makeSuccessfulCommand(infos, signature).toData());
+  }
+}
+
+TEST(BuildValueTest, commandValueMultipleOutputsSerialization) {
+  uint64_t signature = 0xDEADBEEF;
+  basic::FileInfo infos[2] = {};
+  infos[0].size = 1;
+  infos[1].size = 2;
+  
+  // Check that two identical values are equivalent.
+  {
+    BuildValue a = BuildValue::makeSuccessfulCommand(infos, signature);
+    EXPECT_EQ(a.toData(),
+              BuildValue::makeSuccessfulCommand(infos, signature).toData());
+  }
+
+  // Check that a moved complex value is equivalent.
+  {
+    BuildValue tmp = BuildValue::makeSuccessfulCommand(infos, signature);
+    BuildValue a = std::move(tmp);
+    EXPECT_EQ(a.toData(),
+              BuildValue::makeSuccessfulCommand(infos, signature).toData());
+  }
+
+  // Check that an rvalue initialized complex value is equivalent.
+  {
+    BuildValue tmp = BuildValue::makeSuccessfulCommand(infos, signature);
+    BuildValue a{ std::move(tmp) };
+    EXPECT_EQ(a.toData(),
+              BuildValue::makeSuccessfulCommand(infos, signature).toData());
+  }
+}
+
+}
diff --git a/unittests/BuildSystem/CMakeLists.txt b/unittests/BuildSystem/CMakeLists.txt
index e4c8a5d..9da37c5 100644
--- a/unittests/BuildSystem/CMakeLists.txt
+++ b/unittests/BuildSystem/CMakeLists.txt
@@ -1,6 +1,7 @@
 add_llbuild_unittest(BuildSystemTests
-  LaneBasedExecutionQueueTest
   BuildSystemFrontendTest.cpp
+  BuildValueTest.cpp
+  LaneBasedExecutionQueueTest
   TempDir.cpp
   )