diff --git a/programs/random/gen_entropy.c b/programs/random/gen_entropy.c
index 6ae63b7..c60aec9 100644
--- a/programs/random/gen_entropy.c
+++ b/programs/random/gen_entropy.c
@@ -80,7 +80,7 @@
         if( ret != 0 )
         {
             mbedtls_printf( "  failed\n  !  mbedtls_entropy_func returned -%04X\n",
-                            ret );
+                            (unsigned int) ret );
             goto cleanup;
         }