diff --git a/crypto/jpake/jpake.c b/crypto/jpake/jpake.c
index 8e4b633cc..f2489a4ee 100644
--- a/crypto/jpake/jpake.c
+++ b/crypto/jpake/jpake.c
@@ -4,6 +4,7 @@
 #include <openssl/sha.h>
 #include <openssl/err.h>
 #include <memory.h>
+#include <string.h>
 
 /*
  * In the definition, (xa, xb, xc, xd) are Alice's (x1, x2, x3, x4) or