diff --git a/corelib/src/option.cairo b/corelib/src/option.cairo
index 4ad2d768e0f..b64e1ec610e 100644
--- a/corelib/src/option.cairo
+++ b/corelib/src/option.cairo
@@ -306,7 +306,7 @@ pub impl OptionTraitImpl<T> of OptionTrait<T> {
     }
 
     #[inline]
-    fn unwrap_or_else<F, +Drop<F>, impl func: core::ops::Fn<F, ()>[Output: T], +Drop<func::Output>>(
+    fn unwrap_or_else<F, +Drop<F>, impl func: core::ops::FnOnce<F, ()>[Output: T], +Drop<func::Output>>(
         self: Option<T>, f: F,
     ) -> T {
         match self {