diff --git a/cfg/posix.cfg b/cfg/posix.cfg
index 70b490fc2..2b6c6f0e4 100644
--- a/cfg/posix.cfg
+++ b/cfg/posix.cfg
@@ -446,5 +446,5 @@
   <podtype name="pid_t" sign="s"/>
   <podtype name="uid_t" sign="u"/>
   <podtype name="gid_t" sign="u"/>
-  <podtype name="blkcnt_t" sign="u"/>
+  <podtype name="blkcnt_t" sign="s"/>
 </def>