diff --git a/crypto/engine/enginetest.c b/crypto/engine/enginetest.c
index 351b0c742..f02e6f402 100644
--- a/crypto/engine/enginetest.c
+++ b/crypto/engine/enginetest.c
@@ -58,6 +58,7 @@
 
 #include <openssl/e_os2.h>
 #include <stdio.h>
+#include <string.h>
 #include <openssl/buffer.h>
 #include <openssl/crypto.h>
 #include <openssl/engine.h>