diff --git a/ion/pom.xml b/ion/pom.xml
index c115d1027..60d5e86a9 100644
--- a/ion/pom.xml
+++ b/ion/pom.xml
@@ -38,7 +38,7 @@ tree model)
     <dependency>
       <groupId>com.amazon.ion</groupId>
       <artifactId>ion-java</artifactId>
-      <version>1.11.10</version>
+      <version>1.11.11</version>
     </dependency>
 
     <!-- Extends Jackson core, databind -->
diff --git a/ion/src/test/java/com/fasterxml/jackson/dataformat/ion/IonNumberOverflowTest.java b/ion/src/test/java/com/fasterxml/jackson/dataformat/ion/IonNumberOverflowTest.java
index 361d9cda8..11fc69db4 100644
--- a/ion/src/test/java/com/fasterxml/jackson/dataformat/ion/IonNumberOverflowTest.java
+++ b/ion/src/test/java/com/fasterxml/jackson/dataformat/ion/IonNumberOverflowTest.java
@@ -81,7 +81,9 @@ public void testLongAsBigIntegerSize() throws Exception {
         BigInteger bigIntLongValue = new BigInteger(Long.MAX_VALUE + "").subtract(BigInteger.TEN);
         IonParser bigIntLongParser = (IonParser) new IonFactory().createParser(bigIntLongValue.toString());
         assertEquals(JsonToken.VALUE_NUMBER_INT, bigIntLongParser.nextToken());
-        assertEquals(JsonParser.NumberType.BIG_INTEGER, bigIntLongParser.getNumberType());
+        // 23-Oct-2025: Ion 1.11.11+ changed behavior: values that fit in long are now
+        //   classified as LONG (was BIG_INTEGER before)
+        assertEquals(JsonParser.NumberType.LONG, bigIntLongParser.getNumberType());
         assertEquals(JsonParser.NumberTypeFP.UNKNOWN, bigIntLongParser.getNumberTypeFP());
         assertEquals(bigIntLongValue.longValue(), bigIntLongParser.getLongValue());
     }    
diff --git a/release-notes/VERSION-2.x b/release-notes/VERSION-2.x
index ad5e2739f..0571d0354 100644
--- a/release-notes/VERSION-2.x
+++ b/release-notes/VERSION-2.x
@@ -16,7 +16,8 @@ Active maintainers:
 
 2.21.0 (not yet released)
 
-No changes since 2.20
+#623: (ion) Upgrade `ion-java` dep to 1.11.11 (from 1.11.10)
+ (requested by @Shaurya0108)
 
 2.20.1 (not yet released)