diff --git a/src/cfl_sds.c b/src/cfl_sds.c
index 2d886bc..eff66fe 100644
--- a/src/cfl_sds.c
+++ b/src/cfl_sds.c
@@ -212,7 +212,7 @@ cfl_sds_t cfl_sds_printf(cfl_sds_t *sds, const char *fmt, ...)
     va_end(ap);
 
     if (size >= cfl_sds_avail(s)) {
-        tmp = cfl_sds_increase(s, size - flb_sds_avail(s) + 1);
+        tmp = cfl_sds_increase(s, size - cfl_sds_avail(s) + 1);
         if (!tmp) {
             return NULL;
         }