diff --git a/src/backend/final.rs b/src/backend/final.rs
index dd3849a..296d4a3 100644
--- a/src/backend/final.rs
+++ b/src/backend/final.rs
@@ -160,7 +160,7 @@ pub fn produce_func_wasm<FT: FuncTypeSink>(
         locals: vec![],
     };
     wasm.locals
-        .extend(f.locals.iter().map(|ty| ty_to_valty(*ty)));
+        .extend(f.locals.iter().skip(f.n_params).map(|ty| ty_to_valty(*ty)));
     wasm.locals
         .extend(locations.new_locals.iter().map(|ty| ty_to_valty(*ty)));
 
diff --git a/src/frontend.rs b/src/frontend.rs
index 12ce86a..68dd6b0 100644
--- a/src/frontend.rs
+++ b/src/frontend.rs
@@ -109,6 +109,7 @@ fn parse_body<'a>(
     for &param in &module.signatures[my_sig].params[..] {
         ret.locals.push(param);
     }
+    ret.n_params = module.signatures[my_sig].params.len();
     for &r in &module.signatures[my_sig].returns[..] {
         ret.rets.push(r);
     }
diff --git a/src/ir.rs b/src/ir.rs
index c4d88ff..af68d1b 100644
--- a/src/ir.rs
+++ b/src/ir.rs
@@ -53,6 +53,7 @@ impl FuncDecl {
 
 #[derive(Clone, Debug, Default)]
 pub struct FunctionBody {
+    pub n_params: usize,
     pub rets: Vec<Type>,
     pub locals: Vec<Type>,
     pub blocks: Vec<Block>,