diff --git a/fuzz/fuzz_targets/straightline_differential.rs b/fuzz/fuzz_targets/straightline_differential.rs
index 4eeb23a..177edd1 100644
--- a/fuzz/fuzz_targets/straightline_differential.rs
+++ b/fuzz/fuzz_targets/straightline_differential.rs
@@ -121,6 +121,11 @@ fuzz_target!(|module: wasm_smith::ConfiguredModule<Config>| {
     let parsed_module = Module::from_wasm_bytes(&orig_bytes[..]).unwrap();
     let roundtrip_bytes = parsed_module.to_wasm_bytes();
 
+    if let Ok(filename) = std::env::var("FUZZ_DUMP_WASM") {
+        std::fs::write(format!("{}_orig.wasm", filename), &orig_bytes[..]).unwrap();
+        std::fs::write(format!("{}_roundtrip.wasm", filename), &roundtrip_bytes[..]).unwrap();
+    }
+
     let roundtrip_module = wasmtime::Module::new(&engine, &roundtrip_bytes[..])
         .expect("failed to parse roundtripped wasm");
     let roundtrip_instance = wasmtime::Instance::new(&mut store, &roundtrip_module, &[])
diff --git a/src/frontend.rs b/src/frontend.rs
index 68dd6b0..669cb12 100644
--- a/src/frontend.rs
+++ b/src/frontend.rs
@@ -1134,6 +1134,7 @@ impl<'a, 'b> FunctionBodyBuilder<'a, 'b> {
             let values = values.to_vec();
             self.body.end_block(block, Terminator::Return { values });
         }
+        self.cur_block = None;
     }
 
     fn push_block_params(&mut self, num_params: usize) {