diff --git a/pom.xml b/pom.xml
index e14286055..1fe50e6d8 100644
--- a/pom.xml
+++ b/pom.xml
@@ -71,7 +71,7 @@
         <version.mockito>2.7.21</version.mockito>
         <version.hamcrest>2.2</version.hamcrest>
         <version.undertow>2.2.14.Final</version.undertow>
-        <version.itu>1.3.0</version.itu>
+        <version.itu>1.5.1</version.itu>
     </properties>
     <dependencies>
         <dependency>
diff --git a/src/main/java/com/networknt/schema/DateTimeValidator.java b/src/main/java/com/networknt/schema/DateTimeValidator.java
index db3d4bae3..69a082e3c 100644
--- a/src/main/java/com/networknt/schema/DateTimeValidator.java
+++ b/src/main/java/com/networknt/schema/DateTimeValidator.java
@@ -65,7 +65,11 @@ private boolean isLegalDateTime(String string) {
             return tryParse(() -> {
                 try {
                     ITU.parseDateTime(string);
-                } catch (LeapSecondException ignored) {}
+                } catch (LeapSecondException ex) {
+                    if(!ex.isVerifiedValidLeapYearMonth()) {
+                        throw ex;
+                    }
+                }
             });
         } else {
             throw new IllegalStateException("Unknown format: " + formatName);
diff --git a/src/test/resources/draft2019-09/optional/format/date-time.json b/src/test/resources/draft2019-09/optional/format/date-time.json
index b183a8d02..6baa1a564 100644
--- a/src/test/resources/draft2019-09/optional/format/date-time.json
+++ b/src/test/resources/draft2019-09/optional/format/date-time.json
@@ -72,7 +72,7 @@
       },
       {
         "description": "an invalid date-time string with leap second",
-        "data": "1998-10-31T23:59:60Z",
+        "data": "1997-12-31T23:59:60Z",
         "valid": false
       }
     ]
diff --git a/src/test/resources/draft7/optional/format/date-time.json b/src/test/resources/draft7/optional/format/date-time.json
index b183a8d02..6baa1a564 100644
--- a/src/test/resources/draft7/optional/format/date-time.json
+++ b/src/test/resources/draft7/optional/format/date-time.json
@@ -72,7 +72,7 @@
       },
       {
         "description": "an invalid date-time string with leap second",
-        "data": "1998-10-31T23:59:60Z",
+        "data": "1997-12-31T23:59:60Z",
         "valid": false
       }
     ]