diff --git a/src/index.test.ts b/src/index.test.ts
index 8c8e140..90a1ef9 100644
--- a/src/index.test.ts
+++ b/src/index.test.ts
@@ -56,6 +56,14 @@ describe('toHHMM', () => {
     expect(toHHMM(0.01)).toEqual('0:01')
   })
 
+  test('handles time ended in :59 correctly', () => {
+    expect(toHHMM(0.999)).toEqual('0:59')
+  })
+
+  test('handles time ended in :00 correctly', () => {
+    expect(toHHMM(1)).toEqual('1:00')
+  })
+
   test('handles leading and trailing space', () => {
     expect(toHHMM('          -1:30     +  1:44    ')).toEqual('0:14')
   })
diff --git a/src/index.ts b/src/index.ts
index facfafe..b8a27e3 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -33,7 +33,12 @@ export const toHHMM = (input?: number | string): string => {
   const sign = total < 0 ? '-' : ''
   total = Math.abs(total)
   const hours = Math.floor(total / 60)
-  const minutes = Math.round(total) % 60
+  let minutes = total % 60
+  if (minutes >= 59.5 && minutes < 60) {
+    minutes = Math.floor(minutes)
+  } else {
+    minutes = Math.round(minutes)
+  }
   const paddedMinutes = minutes.toString().padStart(2, '0')
 
   return `${sign}${hours}:${paddedMinutes}`