diff --git a/include/grpc++/impl/call.h b/include/grpc++/impl/call.h
index 88056470e37..7fccd95f8e7 100644
--- a/include/grpc++/impl/call.h
+++ b/include/grpc++/impl/call.h
@@ -44,6 +44,8 @@
 #include <memory>
 #include <map>
 
+#include <string.h>
+
 struct grpc_call;
 struct grpc_op;