diff --git a/src/lib.rs b/src/lib.rs
index 64eadda..6b3dd9c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -130,7 +130,7 @@ impl WasiVirt {
     }
 
     pub fn finish(&mut self) -> Result<VirtResult> {
-        let mut config = walrus::ModuleConfig::new();
+        let config = walrus::ModuleConfig::new();
         let mut module = if self.debug {
             config.parse(VIRT_ADAPTER_DEBUG)
         } else {