diff --git a/llvm/tools/dsymutil/DwarfLinkerForBinary.cpp b/llvm/tools/dsymutil/DwarfLinkerForBinary.cpp
--- a/llvm/tools/dsymutil/DwarfLinkerForBinary.cpp
+++ b/llvm/tools/dsymutil/DwarfLinkerForBinary.cpp
@@ -98,6 +98,7 @@
 #include <string>
 #include <system_error>
 #include <tuple>
+#include <unordered_map>
 #include <utility>
 #include <vector>