diff --git a/clang/lib/Lex/ModuleMap.cpp b/clang/lib/Lex/ModuleMap.cpp
index 075a17f..4ef0674 100644
--- a/clang/lib/Lex/ModuleMap.cpp
+++ b/clang/lib/Lex/ModuleMap.cpp
@@ -346,6 +346,9 @@
     ModuleMap::KnownHeader Result;
     // Iterate over all modules that 'File' is part of to find the best fit.
     for (KnownHeader &H : Known->second) {
+      // Prefer a header from the current module over all others.
+      if (H.getModule() == CompilingModule)
+        return MakeResult(H);
       // Cannot use a module if it is unavailable.
       if (!H.getModule()->isAvailable())
         continue;