diff --git a/library/core/src/convert/num.rs b/library/core/src/convert/num.rs
index 4fa5d129bc6..9c0d7e9a1e8 100644
--- a/library/core/src/convert/num.rs
+++ b/library/core/src/convert/num.rs
@@ -49,7 +49,7 @@ macro_rules! impl_from {
             // Rustdocs on the impl block show a "[+] show undocumented items" toggle.
             // Rustdocs on functions do not.
             #[doc = $doc]
-            #[inline]
+            #[inline(always)]
             fn from(small: $Small) -> Self {
                 small as Self
             }