diff --git a/builder/main.py b/builder/main.py
index 4b748bb..0172f32 100644
--- a/builder/main.py
+++ b/builder/main.py
@@ -231,6 +231,7 @@ else:
     else:
         target_firm = env.ElfToBin(
             join("$BUILD_DIR", "${PROGNAME}"), target_elf)
+        env.Depends(target_firm, "checkprogsize")
 
 env.AddPlatformTarget("buildfs", target_firm, target_firm, "Build Filesystem Image")
 AlwaysBuild(env.Alias("nobuild", target_firm))