diff --git a/llvm/lib/Support/BranchProbability.cpp b/llvm/lib/Support/BranchProbability.cpp
index 60d5478a905293..e3763449d16cb9 100644
--- a/llvm/lib/Support/BranchProbability.cpp
+++ b/llvm/lib/Support/BranchProbability.cpp
@@ -16,6 +16,7 @@
 #include "llvm/Support/Format.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
+#include <cmath>
 
 using namespace llvm;