diff --git a/catalog.c b/catalog.c
index a1f43446..4de580dc 100644
--- a/catalog.c
+++ b/catalog.c
@@ -563,11 +563,11 @@ parse_backup_mode(const char *value)
 		v++;
 	len = strlen(v);
 
-	if (len > 0 && pg_strncasecmp("full", v, strlen("full")) == 0)
+	if (len > 0 && pg_strncasecmp("full", v, len) == 0)
 		return BACKUP_MODE_FULL;
-	else if (len > 0 && pg_strncasecmp("page", v, strlen("page")) == 0)
+	else if (len > 0 && pg_strncasecmp("page", v, len) == 0)
 		return BACKUP_MODE_DIFF_PAGE;
-	else if (len > 0 && pg_strncasecmp("ptrack", v, strlen("ptrack")) == 0)
+	else if (len > 0 && pg_strncasecmp("ptrack", v, len) == 0)
 		return BACKUP_MODE_DIFF_PTRACK;
 
 	/* Backup mode is invalid, so leave with an error */
@@ -621,4 +621,4 @@ pgBackupGetPath(const pgBackup *backup, char *path, size_t len, const char *subd
 	free(datetime);
 
 	make_native_path(path);
-}
\ No newline at end of file
+}