diff --git a/hfuzz/Cargo.toml b/hfuzz/Cargo.toml
index d79e9bd..8226f93 100644
--- a/hfuzz/Cargo.toml
+++ b/hfuzz/Cargo.toml
@@ -6,4 +6,5 @@ authors = ["Sergey Pepyakin <s.pepyakin@gmail.com>"]
 [dependencies]
 honggfuzz = "0.5"
 wasmi = { path = ".." }
-
+tempdir = "0.3.6"
+wabt = "0.2.0"
diff --git a/hfuzz/src/lib.rs b/hfuzz/src/lib.rs
deleted file mode 100644
index 31e1bb2..0000000
--- a/hfuzz/src/lib.rs
+++ /dev/null
@@ -1,7 +0,0 @@
-#[cfg(test)]
-mod tests {
-    #[test]
-    fn it_works() {
-        assert_eq!(2 + 2, 4);
-    }
-}
diff --git a/hfuzz/src/main.rs b/hfuzz/src/main.rs
index da4d3f6..cd00346 100644
--- a/hfuzz/src/main.rs
+++ b/hfuzz/src/main.rs
@@ -1,21 +1,56 @@
 #[macro_use] extern crate honggfuzz;
 
-fn main() {
-    // Here you can parse `std::env::args and 
-    // setup / initialize your project
+extern crate wabt;
+extern crate wasmi;
+extern crate tempdir;
 
-    // You have full control over the loop but
-    // you're supposed to call `fuzz` ad vitam aeternam
-    loop {
-        // The fuzz macro gives an arbitrary object (see `arbitrary crate`)
-        // to a closure-like block of code.
-        // For performance reasons, it is recommended that you use the native type
-        // `&[u8]` when possible.
-        // Here, this slice will contain a "random" quantity of "random" data.
-        fuzz!(|data: &[u8]| {
-        });
-    }
+use std::fs::File;
+use std::io::Write;
+use std::process::{Command, Stdio};
 
-    
+fn run_spec(data: &[u8]) -> Result<(), ()> {
+	let temp_dir = tempdir::TempDir::new("spec").unwrap();
+	let mut seed_path = temp_dir.path().to_path_buf();
+	seed_path.push("test.wasm");
+
+	{
+		let mut seedfile =
+			File::create(&seed_path).expect("open temporary file for writing to store fuzzer input");
+		seedfile.write_all(data).expect(
+			"write fuzzer input to temporary file",
+		);
+		seedfile.flush().expect(
+			"flush fuzzer input to temporary file before starting wasm-opt",
+		);
+	}
+
+    let exit_status = Command::new("wasm")
+		.arg("-d")
+        .arg(&seed_path)
+		.stdout(Stdio::null())
+		.stderr(Stdio::null())
+        .status()
+        .expect("failed to execute `wasm`");
+
+	if exit_status.success() {
+		Ok(())
+	} else {
+		Err(())
+	}
 }
 
+fn run_wasmi(data: &[u8]) -> Result<(), ()> {
+	let _ = wasmi::Module::from_buffer(data).map_err(|_| ())?;
+	Ok(())
+}
+
+fn main() {
+    loop {
+        fuzz!(|data: &[u8]| {
+			let wasmi_result = run_wasmi(data);
+			let wasm_result = run_spec(data);
+
+			assert_eq!(wasmi_result.is_ok(), wasm_result.is_ok());
+        });
+    }
+}
diff --git a/hfuzz/test.sh b/hfuzz/test.sh
new file mode 100755
index 0000000..eab042b
--- /dev/null
+++ b/hfuzz/test.sh
@@ -0,0 +1,5 @@
+#!/bin/bash
+
+export HFUZZ_RUN_ARGS="--max_file_size 2048"
+
+rustup run nightly cargo hfuzz run hfuzz