diff --git a/packages/astro/src/transitions/router.ts b/packages/astro/src/transitions/router.ts
index 1e97fa1c898f..a5d06d5c769c 100644
--- a/packages/astro/src/transitions/router.ts
+++ b/packages/astro/src/transitions/router.ts
@@ -305,8 +305,8 @@ async function updateDOM(
 				activeElement instanceof HTMLInputElement ||
 				activeElement instanceof HTMLTextAreaElement
 			) {
-				start && (activeElement.selectionStart = start);
-				end && (activeElement.selectionEnd = end);
+				if (typeof start === 'number') activeElement.selectionStart = start;
+				if (typeof end === 'number') activeElement.selectionEnd = end;
 			}
 		}
 	};