diff --git a/programs/test/benchmark.c b/programs/test/benchmark.c
index 6a1d7890a..0b8c97f06 100644
--- a/programs/test/benchmark.c
+++ b/programs/test/benchmark.c
@@ -57,7 +57,7 @@ int main( void )
 {
     int keysize;
     unsigned long i, j, tsc;
-    unsigned char tmp[32];
+    unsigned char tmp[64];
 #if defined(POLARSSL_ARC4_C)
     arc4_context arc4;
 #endif