diff --git a/src/index.ts b/src/index.ts
index 7461382..978ae1d 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -34,6 +34,7 @@ function parseTimestamp(s: string): number {
 }
 
 function toTimestamp(n: number): string {
+	n = Math.floor(n);
 	return `${Math.floor(n / 60)
 		.toString()
 		.padStart(2, "0")}:${(n % 60).toString().padStart(2, "0")}`;