diff --git a/Cargo.lock b/Cargo.lock
index fe739b9..c4545df 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,6 +2,8 @@
 name = "pumpkin"
 version = "0.1.0"
 dependencies = [
+ "custom_derive 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "newtype_derive 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "ramp 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.3.11 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -15,6 +17,11 @@ dependencies = [
  "winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "custom_derive"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "gcc"
 version = "0.3.17"
@@ -29,6 +36,11 @@ name = "libc"
 version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "newtype_derive"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "ramp"
 version = "0.1.9"
diff --git a/Cargo.toml b/Cargo.toml
index 8fe1d17..3eda19c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,5 +4,7 @@ version = "0.1.0"
 authors = ["Zach Dziura <zcdziura@gmail.com>"]
 
 [dependencies]
+custom_derive = "0.1.2"
+newtype_derive = "0.1.2"
 ramp = "0.1.9"
 rand = "0.3.11"
diff --git a/src/lib.rs b/src/lib.rs
index 3b61826..4943f43 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -34,6 +34,8 @@
 /// ```
 
 extern crate core;
+#[macro_use] extern crate custom_derive;
+#[macro_use] extern crate newtype_derive;
 extern crate ramp;
 extern crate rand;
 
diff --git a/src/prime.rs b/src/prime.rs
index 4c25ca4..150269c 100644
--- a/src/prime.rs
+++ b/src/prime.rs
@@ -96,10 +96,10 @@ static SMALL_PRIMES: [u32; 999] = [3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41,
 /// fact, all operations that you can do with `Int`s, you can do with `Prime`s
 /// as well. `Prime`s simply guarantee that the number you're dealing with is,
 /// a prime number.
-#[derive(Debug)]
-pub struct Prime {
-    bit_length: usize,
-    num: Int
+custom_derive! {
+    #[derive(Debug)]
+    #[derive(NewtypeAdd, NewtypeSub, NewtypeMul, NewtypeDiv)]
+    pub struct Prime(Int); 
 }
 
 impl Prime {
@@ -125,16 +125,14 @@ impl Prime {
             candidate += &two;
         }
 
-        Prime {
-            bit_length: bit_length,
-            num: candidate
-        }
+        Prime(candidate)
     }
 }
 
 impl fmt::Display for Prime {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}", self.num)
+        let &Prime(ref num) = self;
+        write!(f, "{}", num)
     }
 }
 
@@ -260,3 +258,4 @@ mod tests {
         b.iter(|| Prime::new(2048));
     }
 }
+