diff --git a/sledge/Makefile b/sledge/Makefile
index 220a1faf9..0786731c1 100644
--- a/sledge/Makefile
+++ b/sledge/Makefile
@@ -67,7 +67,8 @@ watch: setup
 
 .PHONY: test
 test: setup
-	dune build @_build/dbg/runtest --auto-promote
+	-dune build @_build/dbg/runtest --auto-promote
+	dune build $(FMTS) --auto-promote
 
 .PHONY: ci-test
 ci-test: setup