2 files changed, 9 insertions, 4 deletions
diff --git a/clang/lib/Lex/ModuleMap.cpp b/clang/lib/Lex/ModuleMap.cpp
index 5e103a054d5..69cb574e2a0 100644
--- a/clang/lib/Lex/ModuleMap.cpp
+++ b/clang/lib/Lex/ModuleMap.cpp
@@ -239,6 +239,7 @@ static Module *getTopLevelOrNull(Module *M) {
 }
 
 void ModuleMap::diagnoseHeaderInclusion(Module *RequestingModule,
+                                        bool RequestingModuleIsModuleInterface,
                                         SourceLocation FilenameLoc,
                                         StringRef Filename,
                                         const FileEntry *File) {
@@ -301,7 +302,7 @@ void ModuleMap::diagnoseHeaderInclusion(Module *RequestingModule,
   if (LangOpts.ModulesStrictDeclUse) {
     Diags.Report(FilenameLoc, diag::err_undeclared_use_of_module)
         << RequestingModule->getFullModuleName() << Filename;
-  } else if (RequestingModule) {
+  } else if (RequestingModule && RequestingModuleIsModuleInterface) {
     diag::kind DiagID = RequestingModule->getTopLevelModule()->IsFramework ?
         diag::warn_non_modular_include_in_framework_module :
         diag::warn_non_modular_include_in_module;
diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 320c16dbec2..c36670ca635 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -609,6 +609,7 @@ const FileEntry *Preprocessor::LookupFile(
     ModuleMap::KnownHeader *SuggestedModule,
     bool SkipCache) {
   Module *RequestingModule = getModuleForLocation(FilenameLoc); 
+  bool RequestingModuleIsModuleInterface = !SourceMgr.isInMainFile(FilenameLoc);
 
   // If the header lookup mechanism may be relative to the current inclusion
   // stack, record the parent #includes.
@@ -683,7 +684,8 @@ const FileEntry *Preprocessor::LookupFile(
   if (FE) {
     if (SuggestedModule && !LangOpts.AsmPreprocessor)
       HeaderInfo.getModuleMap().diagnoseHeaderInclusion(
-          RequestingModule, FilenameLoc, Filename, FE);
+          RequestingModule, RequestingModuleIsModuleInterface, FilenameLoc,
+          Filename, FE);
     return FE;
   }
 
@@ -699,7 +701,8 @@ const FileEntry *Preprocessor::LookupFile(
                                                     SuggestedModule))) {
         if (SuggestedModule && !LangOpts.AsmPreprocessor)
           HeaderInfo.getModuleMap().diagnoseHeaderInclusion(
-              RequestingModule, FilenameLoc, Filename, FE);
+              RequestingModule, RequestingModuleIsModuleInterface, FilenameLoc,
+              Filename, FE);
         return FE;
       }
     }
@@ -714,7 +717,8 @@ const FileEntry *Preprocessor::LookupFile(
                 RequestingModule, SuggestedModule))) {
           if (SuggestedModule && !LangOpts.AsmPreprocessor)
             HeaderInfo.getModuleMap().diagnoseHeaderInclusion(
-                RequestingModule, FilenameLoc, Filename, FE);
+                RequestingModule, RequestingModuleIsModuleInterface,
+                FilenameLoc, Filename, FE);
           return FE;
         }
       }