diff --git a/src/lib.rs b/src/lib.rs
index ed7af4c7..dc18526e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -155,7 +155,7 @@
 extern crate alloc;
 
 #[macro_use]
-mod nlimbs;
+mod macros;
 
 #[cfg(feature = "generic-array")]
 mod array;
diff --git a/src/macros.rs b/src/macros.rs
new file mode 100644
index 00000000..7142c214
--- /dev/null
+++ b/src/macros.rs
@@ -0,0 +1,79 @@
+//! Macro definitions which are a part of the public API.
+
+/// Internal implementation detail of [`const_assert_eq`] and [`const_assert_ne`].
+#[doc(hidden)]
+#[macro_export]
+macro_rules! const_assert_n {
+    ($n:expr, $($arg:tt)*) => {{
+        // TODO(tarcieri): gensym a name so it's unique per invocation of the macro?
+        mod __const_assert {
+            pub(super) struct Assert<const N: usize>;
+
+            impl<const N: usize> Assert<N> {
+                pub(super) const ASSERT: () = assert!($($arg)*);
+            }
+        }
+
+        __const_assert::Assert::<$n>::ASSERT
+    }};
+}
+
+/// Const-friendly assertion that two values are equal.
+///
+/// ```
+/// const _: () = crypto_bigint::const_assert_eq!(0, 0, "zero equals zero");
+/// ```
+#[macro_export]
+macro_rules! const_assert_eq {
+    ($left:expr, $right:expr $(,)?) => (
+        $crate::const_assert_n!($left, $left == $right)
+    );
+    ($left:expr, $right:expr, $($arg:tt)+) => (
+        $crate::const_assert_n!($left, $left == $right, $($arg)+)
+    );
+}
+
+/// Const-friendly assertion that two values are NOT equal.
+///
+/// ```
+/// const _: () = crypto_bigint::const_assert_ne!(0, 1, "zero is NOT equal to one");
+/// ```
+#[macro_export]
+macro_rules! const_assert_ne {
+    ($left:expr, $right:expr $(,)?) => (
+        $crate::const_assert_n!($left, $left != $right)
+    );
+    ($left:expr, $right:expr, $($arg:tt)+) => (
+        $crate::const_assert_n!($left, $left != $right, $($arg)+)
+    );
+}
+
+/// Calculate the number of limbs required to represent the given number of bits.
+// TODO(tarcieri): replace with `generic_const_exprs` (rust-lang/rust#76560) when stable
+#[macro_export]
+macro_rules! nlimbs {
+    ($bits:expr) => {
+        $bits / $crate::Limb::BITS
+    };
+}
+
+#[cfg(test)]
+mod tests {
+    #[cfg(target_pointer_width = "32")]
+    #[test]
+    fn nlimbs_for_bits_macro() {
+        assert_eq!(nlimbs!(64), 2);
+        assert_eq!(nlimbs!(128), 4);
+        assert_eq!(nlimbs!(192), 6);
+        assert_eq!(nlimbs!(256), 8);
+    }
+
+    #[cfg(target_pointer_width = "64")]
+    #[test]
+    fn nlimbs_for_bits_macro() {
+        assert_eq!(nlimbs!(64), 1);
+        assert_eq!(nlimbs!(128), 2);
+        assert_eq!(nlimbs!(192), 3);
+        assert_eq!(nlimbs!(256), 4);
+    }
+}
diff --git a/src/nlimbs.rs b/src/nlimbs.rs
deleted file mode 100644
index c5166e7d..00000000
--- a/src/nlimbs.rs
+++ /dev/null
@@ -1,29 +0,0 @@
-/// Calculate the number of limbs required to represent the given number of bits.
-// TODO(tarcieri): replace with `generic_const_exprs` (rust-lang/rust#76560) when stable
-#[macro_export]
-macro_rules! nlimbs {
-    ($bits:expr) => {
-        $bits / $crate::Limb::BITS
-    };
-}
-
-#[cfg(test)]
-mod tests {
-    #[cfg(target_pointer_width = "32")]
-    #[test]
-    fn nlimbs_for_bits_macro() {
-        assert_eq!(nlimbs!(64), 2);
-        assert_eq!(nlimbs!(128), 4);
-        assert_eq!(nlimbs!(192), 6);
-        assert_eq!(nlimbs!(256), 8);
-    }
-
-    #[cfg(target_pointer_width = "64")]
-    #[test]
-    fn nlimbs_for_bits_macro() {
-        assert_eq!(nlimbs!(64), 1);
-        assert_eq!(nlimbs!(128), 2);
-        assert_eq!(nlimbs!(192), 3);
-        assert_eq!(nlimbs!(256), 4);
-    }
-}
diff --git a/src/uint/modular/runtime_mod.rs b/src/uint/modular/runtime_mod.rs
index 3a25d80d..9f15afe0 100644
--- a/src/uint/modular/runtime_mod.rs
+++ b/src/uint/modular/runtime_mod.rs
@@ -269,7 +269,6 @@ impl<const LIMBS: usize> zeroize::Zeroize for DynResidue<LIMBS> {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::nlimbs;
 
     const LIMBS: usize = nlimbs!(64);