diff --git a/llvm/include/llvm/ADT/BitVector.h b/llvm/include/llvm/ADT/BitVector.h
index ab1dd8125bb1..56e5066dba1b 100644
--- a/llvm/include/llvm/ADT/BitVector.h
+++ b/llvm/include/llvm/ADT/BitVector.h
@@ -17,6 +17,7 @@
 #include "llvm/Support/MathExtras.h"
 #include <algorithm>
 #include <cstdlib>
+#include <cassert>
 
 namespace llvm {