diff --git a/programs/pkey/dh_server.c b/programs/pkey/dh_server.c
index 0ac91a4..cc75ee8 100644
--- a/programs/pkey/dh_server.c
+++ b/programs/pkey/dh_server.c
@@ -75,7 +75,7 @@
     int client_fd = -1;
 
     unsigned char buf[2048];
-    unsigned char hash[20];
+    unsigned char hash[32];
     unsigned char buf2[2];
     const char *pers = "dh_server";