diff --git a/src/sds.c b/src/sds.c
index 4adcc06a8..95454e997 100644
--- a/src/sds.c
+++ b/src/sds.c
@@ -206,7 +206,6 @@ void sdsIncrLen(sds s, int incr) {
         assert(sh->len >= (unsigned int)(-incr));
     sh->len += incr;
     sh->free -= incr;
-    assert(sh->free >= 0);
     s[sh->len] = '\0';
 }