diff --git a/src/jws.c b/src/jws.c
index 4e03554..dbbdc1e 100644
--- a/src/jws.c
+++ b/src/jws.c
@@ -173,8 +173,8 @@ static bool _cjose_jws_build_dig_sha(cjose_jws_t *jws, const cjose_jwk_t *jwk, c
 
     if (NULL != jws->dig)
     {
-    	cjose_get_dealloc()(jws->dig);
-    	jws->dig = NULL;
+        cjose_get_dealloc()(jws->dig);
+        jws->dig = NULL;
     }
 
     // allocate buffer for digest
@@ -264,6 +264,12 @@ static bool _cjose_jws_build_dig_hmac_sha(cjose_jws_t *jws, const cjose_jwk_t *j
         goto _cjose_jws_build_dig_hmac_sha_cleanup;
     }
 
+    if (NULL != jws->dig)
+    {
+        cjose_get_dealloc()(jws->dig);
+        jws->dig = NULL;
+    }
+
     // allocate buffer for digest
     jws->dig_len = EVP_MD_size(digest_alg);
     jws->dig = (uint8_t *)cjose_get_alloc()(jws->dig_len);