diff --git a/Makefile b/Makefile
index 73ffd4a..93cd1db 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,4 @@
 apigen.native: $(wildcard *.ml* src/*.ml*)
-	dune clean
 	dune build --profile release
 	cp _build/default/apigen.exe $@
 
@@ -7,7 +6,6 @@ test/%/dune: test/dune-template Makefile
 	sed -e 's/%NAME%/$*/g' $< > $@
 
 check: $(patsubst %,%dune,$(dir $(wildcard test/*/*.api.h)))
-	dune clean
 	BISECT_ENABLE=yes dune runtest
 
 coverage: check
diff --git a/apigen.ml b/apigen.ml
index 91364a3..b72932f 100644
--- a/apigen.ml
+++ b/apigen.ml
@@ -27,5 +27,8 @@ let () =
     | [|_; "-ast"        ; input|] -> main input Ast
     | [|_; "-api"        ; input|] -> main input Api
     | _ -> print_endline "Usage: apigen <file>"
-  with Failure (msg) ->
-    print_endline ("Failure: " ^ msg)
+  with
+  | Failure msg -> print_endline ("Failure: " ^ msg)
+  | ApiLexer.Lexing_error (start_p, token) ->
+      let error = ApiPasses.format_lex_error start_p token in
+      print_endline ("Lexing_error: " ^ error)