diff --git a/src/schema/yaml-1.1/timestamp.ts b/src/schema/yaml-1.1/timestamp.ts
index 2093f3ae..2cdc79bc 100644
--- a/src/schema/yaml-1.1/timestamp.ts
+++ b/src/schema/yaml-1.1/timestamp.ts
@@ -116,5 +116,5 @@ export const timestamp: ScalarTag & { test: RegExp } = {
   },
 
   stringify: ({ value }) =>
-    (value as Date).toISOString().replace(/((T00:00)?:00)?\.000Z$/, '')
+    (value as Date).toISOString().replace(/(T00:00:00)?\.000Z$/, '')
 }
diff --git a/tests/doc/types.ts b/tests/doc/types.ts
index 31658aa3..bd3c0667 100644
--- a/tests/doc/types.ts
+++ b/tests/doc/types.ts
@@ -660,6 +660,7 @@ english: null
 ---
 canonical:        2001-12-15T02:59:43.1Z
 valid iso8601:    2001-12-14t21:59:43.10-05:00
+no secs:          2001-12-15T02:59:00
 space separated:  2001-12-14 21:59:43.10 -5
 no time zone (Z): 2001-12-15 2:59:43.10
 date (00:00:00Z): 2002-12-14`
@@ -671,6 +672,7 @@ date (00:00:00Z): 2002-12-14`
       expect(doc.toJSON()).toMatchObject({
         canonical: '2001-12-15T02:59:43.100Z',
         'valid iso8601': '2001-12-15T02:59:43.100Z',
+        'no secs': '2001-12-15T02:59:00.000Z',
         'space separated': '2001-12-15T02:59:43.100Z',
         'no time zone (Z)': '2001-12-15T02:59:43.100Z',
         'date (00:00:00Z)': '2002-12-14T00:00:00.000Z'
@@ -679,6 +681,7 @@ date (00:00:00Z): 2002-12-14`
 ---
 canonical: 2001-12-15T02:59:43.100Z
 valid iso8601: 2001-12-15T02:59:43.100Z
+no secs: 2001-12-15T02:59:00
 space separated: 2001-12-15T02:59:43.100Z
 no time zone (Z): 2001-12-15T02:59:43.100Z
 date (00:00:00Z): 2002-12-14\n`)