diff --git a/roc_std/src/lib.rs b/roc_std/src/lib.rs
index 99c42dccab..c1f76a4bb2 100644
--- a/roc_std/src/lib.rs
+++ b/roc_std/src/lib.rs
@@ -136,7 +136,7 @@ impl<T> RocList<T> {
     where
         T: Clone,
     {
-        assert!(capacity >= 0);
+        assert!(capacity > 0);
         assert!(slice.len() <= capacity);
 
         let ptr = slice.as_ptr();