diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index d52c4fd77063..bb869077f4cd 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -4186,6 +4186,11 @@ void ASTWriter::WriteMSPointersToMembersPragmaOptions(Sema &SemaRef) {
 
 /// \brief Write the state of 'pragma pack' at the end of the module.
 void ASTWriter::WritePackPragmaOptions(Sema &SemaRef) {
+  // Don't serialize pragma pack state for modules, since it should only take
+  // effect on a per-submodule basis.
+  if (WritingModule)
+    return;
+
   RecordData Record;
   Record.push_back(SemaRef.PackStack.CurrentValue);
   AddSourceLocation(SemaRef.PackStack.CurrentPragmaLocation, Record);
diff --git a/clang/test/Modules/Inputs/module.map b/clang/test/Modules/Inputs/module.map
index dcb60bea8513..b95eec351e86 100644
--- a/clang/test/Modules/Inputs/module.map
+++ b/clang/test/Modules/Inputs/module.map
@@ -265,20 +265,9 @@ module diag_pragma {
   header "diag_pragma.h"
 }
 
-module pragma_pack_set {
-  header "pragma_pack_set.h"
-}
-
-module pragma_pack_push {
-  header "pragma_pack_push.h"
-}
-
-module pragma_pack_empty {
-  header "empty.h"
-}
-
-module pragma_pack_reset_push {
-  header "pragma_pack_reset_push.h"
+module pragma_pack {
+  module set { header "pragma_pack_set.h" }
+  module empty { header "empty.h" }
 }
 
 module dummy {
diff --git a/clang/test/Modules/Inputs/pragma_pack_push.h b/clang/test/Modules/Inputs/pragma_pack_push.h
deleted file mode 100644
index 4fc66e51cf89..000000000000
--- a/clang/test/Modules/Inputs/pragma_pack_push.h
+++ /dev/null
@@ -1,6 +0,0 @@
-
-#pragma pack (push, 4)
-#pragma pack (push, 2)
-#pragma pack (push, 1)
-#pragma pack (pop)
-
diff --git a/clang/test/Modules/Inputs/pragma_pack_reset_push.h b/clang/test/Modules/Inputs/pragma_pack_reset_push.h
deleted file mode 100644
index 18f50a00952c..000000000000
--- a/clang/test/Modules/Inputs/pragma_pack_reset_push.h
+++ /dev/null
@@ -1,4 +0,0 @@
-
-#pragma pack ()
-#pragma pack (push, 4)
-
diff --git a/clang/test/Modules/pragma-pack.c b/clang/test/Modules/pragma-pack.c
deleted file mode 100644
index 9497384c970f..000000000000
--- a/clang/test/Modules/pragma-pack.c
+++ /dev/null
@@ -1,35 +0,0 @@
-// RUN: rm -rf %t
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fmodules -fimplicit-module-maps -x objective-c -emit-module -fmodules-cache-path=%t -fmodule-name=pragma_pack_set %S/Inputs/module.map
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fmodules -fimplicit-module-maps -x objective-c -emit-module -fmodules-cache-path=%t -fmodule-name=pragma_pack_push %S/Inputs/module.map
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fmodules -fimplicit-module-maps -x objective-c -emit-module -fmodules-cache-path=%t -fmodule-name=pragma_pack_empty %S/Inputs/module.map
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fmodules -fimplicit-module-maps -x objective-c -emit-module -fmodules-cache-path=%t -fmodule-name=pragma_pack_reset_push %S/Inputs/module.map
-// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fmodules -fimplicit-module-maps -x objective-c -verify -fmodules-cache-path=%t -I %S/Inputs %s
-// FIXME: When we have a syntax for modules in C, use that.
-
-@import pragma_pack_set;
-
-#pragma pack (show) // expected-warning {{value of #pragma pack(show) == 1}}
-#pragma pack (pop) // expected-warning {{#pragma pack(pop, ...) failed: stack empty}}
-
-@import pragma_pack_push;
-
-#pragma pack (show) // expected-warning {{value of #pragma pack(show) == 2}}
-#pragma pack (pop)
-#pragma pack (show) // expected-warning {{value of #pragma pack(show) == 4}}
-#pragma pack (pop)
-#pragma pack (show) // expected-warning {{value of #pragma pack(show) == 1}}
-#pragma pack (pop) // expected-warning {{#pragma pack(pop, ...) failed: stack empty}}
-
-#pragma pack (16)
-
-@import pragma_pack_empty;
-
-#pragma pack (show) // expected-warning {{value of #pragma pack(show) == 16}}
-#pragma pack (pop) // expected-warning {{#pragma pack(pop, ...) failed: stack empty}}
-
-@import pragma_pack_reset_push;
-
-#pragma pack (show) // expected-warning {{value of #pragma pack(show) == 4}}
-#pragma pack (pop)
-#pragma pack (show) // expected-warning {{value of #pragma pack(show) == 8}}
-
diff --git a/clang/test/Modules/pragma-pack.cpp b/clang/test/Modules/pragma-pack.cpp
new file mode 100644
index 000000000000..96a880c6307b
--- /dev/null
+++ b/clang/test/Modules/pragma-pack.cpp
@@ -0,0 +1,25 @@
+// RUN: rm -rf %t.cache %tlocal.cache
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fmodules \
+// RUN:   -fimplicit-module-maps -x c++ -emit-module \
+// RUN:   -fmodules-cache-path=%t.cache \
+// RUN:   -fmodule-name=pragma_pack %S/Inputs/module.map
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fmodules \
+// RUN:   -fimplicit-module-maps -x c++ -verify \
+// RUN:   -fmodules-cache-path=%t.cache \
+// RUN:   -I%S/Inputs %s
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fmodules \
+// RUN:   -fmodules-local-submodule-visibility \
+// RUN:   -fimplicit-module-maps -x c++ -emit-module \
+// RUN:   -fmodules-cache-path=%tlocal.cache \
+// RUN:   -fmodule-name=pragma_pack %S/Inputs/module.map
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fmodules \
+// RUN:   -fmodules-local-submodule-visibility \
+// RUN:   -fimplicit-module-maps -x c++ -verify \
+// RUN:   -fmodules-cache-path=%tlocal.cache \
+// RUN:   -I%S/Inputs %s
+
+// Check that we don't serialize pragma pack state until/unless including an
+// empty file from the same module (but different submodule) has no effect.
+#pragma pack (show) // expected-warning {{value of #pragma pack(show) == 8}}
+#include "empty.h"
+#pragma pack (show) // expected-warning {{value of #pragma pack(show) == 8}}