diff --git a/macros/Cargo.toml b/macros/Cargo.toml
index 2fa2563..61e25c6 100644
--- a/macros/Cargo.toml
+++ b/macros/Cargo.toml
@@ -14,6 +14,7 @@ quote = "0.1.3"
 syn = "0.6.0"
 
 [dev-dependencies]
+compiletest_rs = "0.2.2"
 
 [dev-dependencies.num]
 path = ".."
diff --git a/macros/src/lib.rs b/macros/src/lib.rs
index d85218c..3283bb0 100644
--- a/macros/src/lib.rs
+++ b/macros/src/lib.rs
@@ -19,6 +19,7 @@ extern crate rustc_macro;
 use rustc_macro::TokenStream;
 
 use syn::Body::Enum;
+use syn::VariantData::Unit;
 
 #[rustc_macro_derive(FromPrimitive)]
 pub fn from_primitive(input: TokenStream) -> TokenStream {
@@ -29,13 +30,22 @@ pub fn from_primitive(input: TokenStream) -> TokenStream {
 
     let variants = match ast.body {
         Enum(ref variants) => variants,
-        _ => panic!("`FromPrimitive` can be applied only to the enums, {} is not an enum", name),
+        _ => {
+            panic!("`FromPrimitive` can be applied only to the enums, {} is not an enum",
+                   name)
+        }
     };
 
     let mut idx = 0;
     let variants: Vec<_> = variants.iter()
         .map(|variant| {
             let ident = &variant.ident;
+            match variant.data {
+                Unit => (),
+                _ => {
+                    panic!("`FromPrimitive` can be applied only to unitary enums, {}::{} is either struct or tuple", name, ident)
+                },
+            }
             if let Some(val) = variant.discriminant {
                 idx = val.value;
             }
diff --git a/macros/tests/compile-fail/derive_on_struct.rs b/macros/tests/compile-fail/derive_on_struct.rs
new file mode 100644
index 0000000..1f21081
--- /dev/null
+++ b/macros/tests/compile-fail/derive_on_struct.rs
@@ -0,0 +1,25 @@
+
+// Copyright 2013-2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(rustc_macro)]
+
+extern crate num;
+#[macro_use]
+extern crate num_macros;
+
+#[derive(Debug, PartialEq, FromPrimitive)] //~ ERROR
+struct Color {
+    r: u8,
+    g: u8,
+    b: u8,
+}
+
+fn main() {}
diff --git a/macros/tests/compile-fail/enum_with_associated_data.rs b/macros/tests/compile-fail/enum_with_associated_data.rs
new file mode 100644
index 0000000..0fef268
--- /dev/null
+++ b/macros/tests/compile-fail/enum_with_associated_data.rs
@@ -0,0 +1,24 @@
+
+// Copyright 2013-2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(rustc_macro)]
+
+extern crate num;
+#[macro_use]
+extern crate num_macros;
+
+#[derive(Debug, PartialEq, FromPrimitive)] //~ ERROR
+enum Color {
+    Rgb(u8, u8, u8),
+    Hsv(u8, u8, u8),
+}
+
+fn main() {}
diff --git a/macros/tests/compiletest.rs b/macros/tests/compiletest.rs
new file mode 100644
index 0000000..27c212b
--- /dev/null
+++ b/macros/tests/compiletest.rs
@@ -0,0 +1,25 @@
+extern crate compiletest_rs as compiletest;
+
+use std::path::PathBuf;
+use std::env::var;
+
+fn run_mode(mode: &'static str) {
+    let mut config = compiletest::default_config();
+
+    let cfg_mode = mode.parse().ok().expect("Invalid mode");
+
+    config.target_rustcflags = Some("-L target/debug/ -L target/debug/deps/".to_owned());
+    if let Ok(name) = var::<&str>("TESTNAME") {
+        let s : String = name.to_owned();
+        config.filter = Some(s)
+    }
+    config.mode = cfg_mode;
+    config.src_base = PathBuf::from(format!("tests/{}", mode));
+
+    compiletest::run_tests(&config);
+}
+
+#[test]
+fn compile_test() {
+    run_mode("compile-fail");
+}
diff --git a/macros/tests/empty_enum.rs b/macros/tests/empty_enum.rs
new file mode 100644
index 0000000..3a3d55a
--- /dev/null
+++ b/macros/tests/empty_enum.rs
@@ -0,0 +1,26 @@
+
+// Copyright 2013-2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(rustc_macro)]
+
+extern crate num;
+#[macro_use]
+extern crate num_macros;
+
+#[derive(Debug, PartialEq, FromPrimitive)]
+enum Color {}
+
+#[test]
+fn test_empty_enum() {
+    let v: [Option<Color>; 1] = [num::FromPrimitive::from_u64(0)];
+
+    assert_eq!(v, [None]);
+}