diff --git a/Makefile b/Makefile
index fd67fb7b9..0979a2603 100644
--- a/Makefile
+++ b/Makefile
@@ -38,11 +38,7 @@ clean:
 
 .PHONY: reformat
 reformat:
-	mill -i __.reformat
-
-.PHONY: checkformat
-checkformat:
-	mill -i __.checkFormat
+	nix develop ".#t1.elaborator" -c bash -c 'eval "$$formatHook"'
 
 .PHONY: list-configs
 list-configs:
diff --git a/nix/t1/mill-modules.nix b/nix/t1/mill-modules.nix
index 85e81f885..26a720d83 100644
--- a/nix/t1/mill-modules.nix
+++ b/nix/t1/mill-modules.nix
@@ -80,6 +80,18 @@ let
       CIRCT_INSTALL_PATH = circt-full;
       JEXTRACT_INSTALL_PATH = jextract-21;
       JAVA_TOOL_OPTIONS = "--enable-preview";
+      formatHook = ''
+        targets=( $(mill -i resolve _.reformat) )
+        localTargets=()
+        for t in ''${targets[@]}; do
+          if ! mill -i show "''${t//reformat/sources}" | grep -q dependencies; then
+            localTargets+=($t)
+          fi
+        done
+        for t in ''${localTargets[@]}; do
+          mill -i "$t"
+        done
+      '';
     };
 
     outputs = [ "out" "omreader" "elaborator" "t1package" ];