diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index efa188f..4af5fab 100644
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -1180,16 +1180,17 @@
   const FileEntry *File = LookupFile(
       Filename, isAngled, LookupFrom, CurDir,
       Callbacks ? &SearchPath : NULL, Callbacks ? &RelativePath : NULL);
-  if (File == 0) {
-    Diag(FilenameTok, diag::err_pp_file_not_found) << Filename;
-    return;
-  }
 
   // Notify the callback object that we've seen an inclusion directive.
   if (Callbacks)
     Callbacks->InclusionDirective(HashLoc, IncludeTok, Filename, isAngled, File,
                                   End, SearchPath, RelativePath);
 
+  if (File == 0) {
+    Diag(FilenameTok, diag::warn_pp_file_not_found) << Filename;
+    return;
+  }
+
   // The #included file will be considered to be a system header if either it is
   // in a system include directory, or if the #includer is a system include
   // header.
diff --git a/lib/Lex/Pragma.cpp b/lib/Lex/Pragma.cpp
index bd2ac1b..e6b28c1 100644
--- a/lib/Lex/Pragma.cpp
+++ b/lib/Lex/Pragma.cpp
@@ -368,7 +368,7 @@
   const DirectoryLookup *CurDir;
   const FileEntry *File = LookupFile(Filename, isAngled, 0, CurDir, NULL, NULL);
   if (File == 0) {
-    Diag(FilenameTok, diag::err_pp_file_not_found) << Filename;
+    Diag(FilenameTok, diag::warn_pp_file_not_found) << Filename;
     return;
   }