1 files changed, 2 insertions, 2 deletions
diff --git a/src/sds.h b/src/sds.h
index ac99b80..4c7ae5f 100644
--- a/src/sds.h
+++ b/src/sds.h
@@ -46,12 +46,12 @@ static inline struct sdshdr * sdsheader(const sds s) {
 }
 
 static inline size_t sdslen(const sds s) {
-    struct sdshdr *sh = s - (sizeof (struct sdshdr));
+    struct sdshdr *sh = sdsheader(s);
     return sh->len;
 }
 
 static inline size_t sdsavail(const sds s) {
-    struct sdshdr *sh = s - (sizeof (struct sdshdr));
+    struct sdshdr *sh = sdsheader(s);
     return sh->free;
 }