diff --git a/src/psl.c b/src/psl.c
index 72ea836..3d60ab0 100644
--- a/src/psl.c
+++ b/src/psl.c
@@ -1594,20 +1594,19 @@ psl_error_t psl_str_to_utf8lower(const char *str, const char *encoding _UNUSED,
 {
 	int ret = PSL_ERR_INVALID_ARG;
 
-	if (lower)
-		*lower = NULL;
-
 	if (!str)
 		return PSL_ERR_INVALID_ARG;
 
 	/* shortcut to avoid costly conversion */
 	if (_str_is_ascii(str)) {
 		if (lower) {
-			char *p;
+			char *p, *tmp;
 
-			if (!(*lower = strdup(str)))
+			if (!(tmp = strdup(str)))
 				return PSL_ERR_NO_MEM;
 
+			*lower = tmp;
+
 			/* convert ASCII string to lowercase */
 			for (p = *lower; *p; p++)
 				if (isupper(*p))
@@ -1654,7 +1653,11 @@ psl_error_t psl_str_to_utf8lower(const char *str, const char *encoding _UNUSED,
 					ret = PSL_SUCCESS;
 					if (lower) {
 						if (str_length < 256) {
-							if (!(*lower = strdup(utf8_lower)))
+							char *tmp = strdup(utf8_lower);
+
+							if (tmp)
+								*lower = tmp;
+							else
 								ret = PSL_ERR_NO_MEM;
 						} else {
 							*lower = utf8_lower;
diff --git a/tests/test-registrable-domain.c b/tests/test-registrable-domain.c
index 819216b..444d5d3 100644
--- a/tests/test-registrable-domain.c
+++ b/tests/test-registrable-domain.c
@@ -53,7 +53,7 @@ static int
 static void testx(const psl_ctx_t *psl, const char *domain, const char *encoding, const char *lang, const char *expected_result)
 {
 	const char *result;
-	char *lower;
+	char *lower = NULL;
 	int rc;
 
 	/* just to cover special code paths for valgrind checking */
@@ -67,8 +67,6 @@ static void testx(const psl_ctx_t *psl, const char *domain, const char *encoding
 		/* if we do not runtime support, test failure have to be skipped */
 		failed++;
 		printf("psl_str_to_utf8lower(%s)=%d\n", domain ? domain : "NULL", rc);
-
-		free(lower);
 		return;
 	}
 #endif
diff --git a/tools/psl.c b/tools/psl.c
index 7c082cd..bcf787f 100644
--- a/tools/psl.c
+++ b/tools/psl.c
@@ -164,15 +164,15 @@ int main(int argc, const char *const *argv)
 				else if (mode == 4) {
 					char *cookie_domain_lower;
 
-					if ((rc = psl_str_to_utf8lower(domain, NULL, NULL, &cookie_domain_lower)) != PSL_SUCCESS)
-						fprintf(stderr, "%s: Failed to convert cookie domain '%s' to lowercase UTF-8 (%d)\n", domain, cookie_domain, rc);
-					else
+					if ((rc = psl_str_to_utf8lower(domain, NULL, NULL, &cookie_domain_lower)) == PSL_SUCCESS) {
 						printf("%s: %d\n", domain, psl_is_cookie_domain_acceptable(psl, lower, cookie_domain));
-
-					free(cookie_domain_lower);
+						free(cookie_domain_lower);
+					} else
+						fprintf(stderr, "%s: Failed to convert cookie domain '%s' to lowercase UTF-8 (%d)\n", domain, cookie_domain, rc);
 				}
 
-				free(lower);
+				if (rc == PSL_SUCCESS)
+					free(lower);
 			}
 
 			psl_free(psl);