diff --git a/test/evp_extra_test.c b/test/evp_extra_test.c
index 33c5a5b7e6..b241387b5e 100644
--- a/test/evp_extra_test.c
+++ b/test/evp_extra_test.c
@@ -2070,7 +2070,7 @@ static int get_cmac_val(EVP_PKEY *pkey, unsigned char *mac)
 {
     EVP_MD_CTX *mdctx = EVP_MD_CTX_new();
     const char msg[] = "Hello World";
-    size_t maclen;
+    size_t maclen = AES_BLOCK_SIZE;
     int ret = 1;
 
     if (!TEST_ptr(mdctx)