diff --git a/Makefile b/Makefile
index 9ecba1ce2d..b736b04906 100644
--- a/Makefile
+++ b/Makefile
@@ -479,7 +479,7 @@ contracts/test/prover/proofs/rust-%.json: $(arbitrator_cases)/rust/$(wasm32_wasi
 	$(prover_bin) $< $(arbitrator_wasm_lib_flags) -o $@ -b --allow-hostapi --require-success --inbox-add-stub-headers --inbox $(arbitrator_cases)/rust/data/msg0.bin --inbox $(arbitrator_cases)/rust/data/msg1.bin --delayed-inbox $(arbitrator_cases)/rust/data/msg0.bin --delayed-inbox $(arbitrator_cases)/rust/data/msg1.bin --preimages target/testdata/preimages.bin --with-forwarder
 
 contracts/test/prover/proofs/go.json: $(arbitrator_cases)/go/testcase.wasm $(prover_bin) $(arbitrator_wasm_libs) target/testdata/preimages.bin $(arbitrator_tests_link_deps) $(arbitrator_cases)/user.wasm
-	$(prover_bin) $< $(arbitrator_wasm_lib_flags) -o $@ -b --require-success --preimages target/testdata/preimages.bin  --stylus-modules $(arbitrator_cases)/user.wasm --with-forwarder
+	$(prover_bin) $< $(arbitrator_wasm_lib_flags) -o $@ -b --require-success --preimages target/testdata/preimages.bin --stylus-modules $(arbitrator_cases)/user.wasm --with-forwarder
 
 # avoid testing user.wasm in onestepproofs. It can only run as stylus program.
 contracts/test/prover/proofs/user.json: