diff --git a/lib/Lex/PTHLexer.cpp b/lib/Lex/PTHLexer.cpp
index 63f2722e99..85d009b4cb 100644
--- a/lib/Lex/PTHLexer.cpp
+++ b/lib/Lex/PTHLexer.cpp
@@ -244,7 +244,7 @@ PTHManager::PTHManager(const llvm::MemoryBuffer* buf, void* fileLookup,
 PTHManager::~PTHManager() {
   delete Buf;
   delete (PTHFileLookup*) FileLookup;
-  delete [] (IdentifierInfo**) PerIDCache;
+  assert(PerIDCache); free(PerIDCache);
 }
 
 PTHManager* PTHManager::Create(const std::string& file, Preprocessor& PP) {