diff --git a/stl/inc/limits b/stl/inc/limits
index f93a63ac90f..bfe6ee02843 100644
--- a/stl/inc/limits
+++ b/stl/inc/limits
@@ -1058,9 +1058,14 @@ _NODISCARD int _Checked_x86_x64_countr_zero(const _Ty _Val) noexcept {
     constexpr _Ty _Max    = (numeric_limits<_Ty>::max)();
 
 #ifndef __AVX2__
-    const bool _Definitely_have_tzcnt = __isa_available >= __ISA_AVAILABLE_AVX2;
-    if (!_Definitely_have_tzcnt && _Val == 0) {
-        return _Digits;
+    // Because the widening done below will always give a non-0 value, checking for tzcnt
+    // is not required for 8-bit and 16-bit since the only difference in behavior between
+    // bsf and tzcnt is when the value is 0.
+    if constexpr (_Digits > 16) {
+        const bool _Definitely_have_tzcnt = __isa_available >= __ISA_AVAILABLE_AVX2;
+        if (!_Definitely_have_tzcnt && _Val == 0) {
+            return _Digits;
+        }
     }
 #endif // __AVX2__