diff --git a/programs/pkey/pk_verify.c b/programs/pkey/pk_verify.c
index 3afa34a..1623708 100644
--- a/programs/pkey/pk_verify.c
+++ b/programs/pkey/pk_verify.c
@@ -68,7 +68,7 @@
     int ret = 1;
     size_t i;
     pk_context pk;
-    unsigned char hash[20];
+    unsigned char hash[32];
     unsigned char buf[POLARSSL_MPI_MAX_SIZE];
     char filename[512];