diff --git a/os/various/syscalls.c b/os/various/syscalls.c
index fd2449b40..b3918976c 100644
--- a/os/various/syscalls.c
+++ b/os/various/syscalls.c
@@ -134,7 +134,6 @@ caddr_t _sbrk_r(struct _reent *r, int incr)
 
   chDbgCheck(incr > 0, "_sbrk_r");
 
-  (void)r;
   p = chCoreAlloc((size_t)incr);
   if (p == NULL) {
     __errno_r(r) = ENOMEM;
@@ -142,6 +141,7 @@ caddr_t _sbrk_r(struct _reent *r, int incr)
   }
   return (caddr_t)p;
 #else
+  (void)incr;
   __errno_r(r) = ENOMEM;
   return (caddr_t)-1;
 #endif