diff --git a/tools/libclang/CXTranslationUnit.h b/tools/libclang/CXTranslationUnit.h
index 699b74a..bdc171c 100644
--- a/tools/libclang/CXTranslationUnit.h
+++ b/tools/libclang/CXTranslationUnit.h
@@ -39,6 +39,8 @@
 CXTranslationUnitImpl *MakeCXTranslationUnit(CIndexer *CIdx, ASTUnit *AU);
 
 static inline ASTUnit *getASTUnit(CXTranslationUnit TU) {
+  if (!TU)
+    return 0;
   return TU->TheASTUnit;
 }