diff --git a/lib/ClangImporter/ClangImporter.cpp b/lib/ClangImporter/ClangImporter.cpp
index e1f45f3da6f31..2463ab049ce7a 100644
--- a/lib/ClangImporter/ClangImporter.cpp
+++ b/lib/ClangImporter/ClangImporter.cpp
@@ -3310,7 +3310,7 @@ ClangModuleUnit::ClangModuleUnit(ModuleDecl &M,
     clangModule(clangModule) {
   // Capture the file metadata before it goes away.
   if (clangModule)
-    ASTSourceDescriptor = {*clangModule};
+    ASTSourceDescriptor = {*const_cast<clang::Module *>(clangModule)};
 }
 
 StringRef ClangModuleUnit::getModuleDefiningPath() const {