diff --git a/crates/integration/src/lib.rs b/crates/integration/src/lib.rs
index ca2a618..4eb3757 100644
--- a/crates/integration/src/lib.rs
+++ b/crates/integration/src/lib.rs
@@ -36,7 +36,7 @@ mod tests {
     fn flipper() {
         let code = crate::compile_blob("Flipper", include_str!("../contracts/flipper.sol"));
         let state = State::new(0xcde4efa9u32.to_be_bytes().to_vec());
-        let (instance, export) = mock_runtime::prepare(&code);
+        let (instance, export) = mock_runtime::prepare(&code, None);
 
         let state = crate::mock_runtime::call(state, &instance, export);
         assert_eq!(state.output.flags, 0);
@@ -66,7 +66,7 @@ mod tests {
         let input = TestSha3::testCall::new((param.to_string(),)).abi_encode();
 
         let state = State::new(input);
-        let (instance, export) = mock_runtime::prepare(&code);
+        let (instance, export) = mock_runtime::prepare(&code, None);
         let state = crate::mock_runtime::call(state, &instance, export);
 
         assert_eq!(state.output.flags, 0);
@@ -94,7 +94,7 @@ mod tests {
         input.extend_from_slice(&param.to_be_bytes::<32>());
 
         let state = State::new(input);
-        let (instance, export) = mock_runtime::prepare(&code);
+        let (instance, export) = mock_runtime::prepare(&code, None);
         let state = crate::mock_runtime::call(state, &instance, export);
 
         assert_eq!(state.output.flags, 0);
@@ -114,7 +114,7 @@ mod tests {
         input.extend_from_slice(&param.to_be_bytes::<32>());
 
         let state = State::new(input);
-        let (instance, export) = mock_runtime::prepare(&code);
+        let (instance, export) = mock_runtime::prepare(&code, None);
         let state = crate::mock_runtime::call(state, &instance, export);
 
         assert_eq!(state.output.flags, 0);
diff --git a/crates/integration/src/mock_runtime.rs b/crates/integration/src/mock_runtime.rs
index 789a28e..993329f 100644
--- a/crates/integration/src/mock_runtime.rs
+++ b/crates/integration/src/mock_runtime.rs
@@ -192,10 +192,10 @@ fn link_host_functions(engine: &Engine) -> Linker<State> {
     linker
 }
 
-pub fn prepare(code: &[u8]) -> (InstancePre<State>, ExportIndex) {
+pub fn prepare(code: &[u8], config: Option<Config>) -> (InstancePre<State>, ExportIndex) {
     let blob = ProgramBlob::parse(code).unwrap();
 
-    let engine = Engine::new(&Config::new()).unwrap();
+    let engine = Engine::new(&config.unwrap_or_default()).unwrap();
 
     let mut module_config = ModuleConfig::new();
     module_config.set_gas_metering(Some(GasMeteringKind::Sync));