diff --git a/components/camel-grok/pom.xml b/components/camel-grok/pom.xml
index e9aea6eb15720..7c746cb031d6e 100644
--- a/components/camel-grok/pom.xml
+++ b/components/camel-grok/pom.xml
@@ -39,7 +39,7 @@
             <artifactId>camel-support</artifactId>
         </dependency>
         <dependency>
-            <groupId>io.krakens</groupId>
+            <groupId>io.github.whatap</groupId>
             <artifactId>java-grok</artifactId>
             <version>${java-grok-version}</version>
         </dependency>
diff --git a/components/camel-grok/src/main/java/org/apache/camel/component/grok/GrokDataFormat.java b/components/camel-grok/src/main/java/org/apache/camel/component/grok/GrokDataFormat.java
index 5c9ec85b9f471..9a75abe69f365 100644
--- a/components/camel-grok/src/main/java/org/apache/camel/component/grok/GrokDataFormat.java
+++ b/components/camel-grok/src/main/java/org/apache/camel/component/grok/GrokDataFormat.java
@@ -26,9 +26,9 @@
 import java.util.*;
 import java.util.stream.Stream;
 
-import io.krakens.grok.api.Grok;
-import io.krakens.grok.api.GrokCompiler;
-import io.krakens.grok.api.Match;
+import io.whatap.grok.api.Grok;
+import io.whatap.grok.api.GrokCompiler;
+import io.whatap.grok.api.Match;
 import org.apache.camel.CamelContext;
 import org.apache.camel.CamelContextAware;
 import org.apache.camel.Exchange;
diff --git a/components/camel-grok/src/test/java/org/apache/camel/component/grok/GrokOptionalOptionsTest.java b/components/camel-grok/src/test/java/org/apache/camel/component/grok/GrokOptionalOptionsTest.java
index 46c82e00e87c6..779e803322d6c 100644
--- a/components/camel-grok/src/test/java/org/apache/camel/component/grok/GrokOptionalOptionsTest.java
+++ b/components/camel-grok/src/test/java/org/apache/camel/component/grok/GrokOptionalOptionsTest.java
@@ -19,19 +19,15 @@
 import java.util.List;
 import java.util.Map;
 
-import io.krakens.grok.api.exception.GrokException;
-import org.apache.camel.CamelExecutionException;
 import org.apache.camel.RoutesBuilder;
 import org.apache.camel.builder.RouteBuilder;
 import org.apache.camel.spi.DataFormat;
 import org.apache.camel.test.junit6.CamelTestSupport;
 import org.junit.jupiter.api.Test;
 
-import static org.apache.camel.test.junit6.TestSupport.assertIsInstanceOf;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
-import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public class GrokOptionalOptionsTest extends CamelTestSupport {
@@ -40,23 +36,19 @@ protected RoutesBuilder createRouteBuilder() {
         return new RouteBuilder() {
             @Override
             public void configure() {
-                DataFormat grokFlattenedTrue = new GrokDataFormat("%{INT:i} %{INT:i}")
-                        .setFlattened(true);
-                DataFormat grokFlattenedFalse = new GrokDataFormat("%{INT:i} %{INT:i}")
-                        .setFlattened(false);
+                DataFormat grokMultipleInt = new GrokDataFormat("%{INT:i:integer} %{INT:j:integer}");
 
                 DataFormat grokNamedOnlyTrue = new GrokDataFormat("%{URI:website}")
                         .setNamedOnly(true);
                 DataFormat grokNamedOnlyFalse = new GrokDataFormat("%{URI:website}")
                         .setNamedOnly(false);
 
-                DataFormat grokAllowMultipleMatchesPerLineTrue = new GrokDataFormat("%{INT:i}")
+                DataFormat grokAllowMultipleMatchesPerLineTrue = new GrokDataFormat("%{INT:i:integer}")
                         .setAllowMultipleMatchesPerLine(true);
-                DataFormat grokAllowMultipleMatchesPerLineFalse = new GrokDataFormat("%{INT:i}")
+                DataFormat grokAllowMultipleMatchesPerLineFalse = new GrokDataFormat("%{INT:i:integer}")
                         .setAllowMultipleMatchesPerLine(false);
 
-                from("direct:flattenedTrue").unmarshal(grokFlattenedTrue);
-                from("direct:flattenedFalse").unmarshal(grokFlattenedFalse);
+                from("direct:multipleInt").unmarshal(grokMultipleInt);
                 from("direct:namedOnlyTrue").unmarshal(grokNamedOnlyTrue);
                 from("direct:namedOnlyFalse").unmarshal(grokNamedOnlyFalse);
                 from("direct:allowMultipleMatchesPerLineTrue").unmarshal(grokAllowMultipleMatchesPerLineTrue);
@@ -69,16 +61,15 @@ public void configure() {
     @Test
     @SuppressWarnings("unchecked")
     public void testFlattened() {
-        Map<String, Object> flattenedFalse = template.requestBody("direct:flattenedFalse", "123 456", Map.class);
-        assertNotNull(flattenedFalse);
-        assertTrue(flattenedFalse.containsKey("i"));
-        assertTrue(flattenedFalse.get("i") instanceof List);
-        assertEquals("123", ((List) flattenedFalse.get("i")).get(0));
-        assertEquals("456", ((List) flattenedFalse.get("i")).get(1));
+        Map<String, Object> multipleInt = template.requestBody("direct:multipleInt", "123 456", Map.class);
+        assertNotNull(multipleInt);
+        assertTrue(multipleInt.containsKey("i"));
+        assertTrue(multipleInt.get("i") instanceof Integer);
+        assertEquals(123, multipleInt.get("i"));
 
-        CamelExecutionException e = assertThrows(CamelExecutionException.class,
-                () -> template.requestBody("direct:flattenedTrue", "1 2"));
-        assertIsInstanceOf(GrokException.class, e.getCause());
+        assertTrue(multipleInt.containsKey("j"));
+        assertTrue(multipleInt.get("j") instanceof Integer);
+        assertEquals(456, multipleInt.get("j"));
     }
 
     @Test
@@ -110,9 +101,9 @@ public void testAllowMultipleMatchesPerLine() {
                 List.class);
         assertNotNull(allowMultipleMatchesPerLineTrue);
         assertEquals(3, allowMultipleMatchesPerLineTrue.size());
-        assertEquals("1", allowMultipleMatchesPerLineTrue.get(0).get("i"));
-        assertEquals("2", allowMultipleMatchesPerLineTrue.get(1).get("i"));
-        assertEquals("3", allowMultipleMatchesPerLineTrue.get(2).get("i"));
+        assertEquals(1, allowMultipleMatchesPerLineTrue.get(0).get("i"));
+        assertEquals(2, allowMultipleMatchesPerLineTrue.get(1).get("i"));
+        assertEquals(3, allowMultipleMatchesPerLineTrue.get(2).get("i"));
 
         List<Map<String, Object>> allowMultipleMatchesPerLineFalse = template.requestBody(
                 "direct:allowMultipleMatchesPerLineFalse",
@@ -120,8 +111,8 @@ public void testAllowMultipleMatchesPerLine() {
                 List.class);
         assertNotNull(allowMultipleMatchesPerLineFalse);
         assertEquals(2, allowMultipleMatchesPerLineFalse.size());
-        assertEquals("1", allowMultipleMatchesPerLineFalse.get(0).get("i"));
-        assertEquals("3", allowMultipleMatchesPerLineFalse.get(1).get("i"));
+        assertEquals(1, allowMultipleMatchesPerLineFalse.get(0).get("i"));
+        assertEquals(3, allowMultipleMatchesPerLineFalse.get(1).get("i"));
 
     }
 }
diff --git a/components/camel-grok/src/test/java/org/apache/camel/component/grok/GrokPatternsTest.java b/components/camel-grok/src/test/java/org/apache/camel/component/grok/GrokPatternsTest.java
index b8e0393616bbc..405c2fa69dd39 100644
--- a/components/camel-grok/src/test/java/org/apache/camel/component/grok/GrokPatternsTest.java
+++ b/components/camel-grok/src/test/java/org/apache/camel/component/grok/GrokPatternsTest.java
@@ -57,11 +57,11 @@ public static List<Arguments> data() {
                 Arguments.of("%{NUMBER:num}", "number is 123.", test("num", "123")),
                 Arguments.of("%{NUMBER:num:integer}", "number is 123.", test("num", 123)),
                 Arguments.of("%{IP:ip}", "my ip is 192.168.0.1", test("ip", "192.168.0.1")),
-                Arguments.of("%{TIMESTAMP_ISO8601:timestamp}", "This test was created at 2019-05-26T10:54:15Z test plain",
-                        test("timestamp", "2019-05-26T10:54:15Z")),
-                Arguments.of("%{TIMESTAMP_ISO8601:timestamp:date}",
+                Arguments.of("%{TIMESTAMP_ISO8601:log_timestamp}", "This test was created at 2019-05-26T10:54:15Z test plain",
+                        test("log_timestamp", "2019-05-26T10:54:15Z")),
+                Arguments.of("%{TIMESTAMP_ISO8601:log_timestamp:date}",
                         "This test was created at 2019-05-26T10:54:15Z test convert",
-                        test("timestamp", Instant.ofEpochSecond(1558868055))));
+                        test("log_timestamp", Instant.ofEpochSecond(1558868055))));
     }
 
     @Override
diff --git a/docs/user-manual/modules/ROOT/pages/camel-4x-upgrade-guide-4_21.adoc b/docs/user-manual/modules/ROOT/pages/camel-4x-upgrade-guide-4_21.adoc
index 7e42bfa2cdd49..e4c1f7748a93a 100644
--- a/docs/user-manual/modules/ROOT/pages/camel-4x-upgrade-guide-4_21.adoc
+++ b/docs/user-manual/modules/ROOT/pages/camel-4x-upgrade-guide-4_21.adoc
@@ -13,6 +13,11 @@ See the xref:camel-upgrade-recipes-tool.adoc[documentation] page for details.
 
 == Upgrading Camel 4.20 to 4.21
 
+=== camel-grok - potential breaking change
+
+The library used for Camel Grok component has been migrated from no more maintained `io.krakens:java-grok` to its fork `io.github.whatap:java-grok`.
+It implies small differences listed https://github.com/whatap/java-grok#what-is-different-from-iokrakensjava-grok[here].
+
 === camel-core
 
 The `org.apache.camel.support.DefaultHeaderFilterStrategy` changed default setting for lowercase from `false` to `true`.
diff --git a/parent/pom.xml b/parent/pom.xml
index f6821883ad603..ce8100d34489d 100644
--- a/parent/pom.xml
+++ b/parent/pom.xml
@@ -260,7 +260,7 @@
         <jandex-version>3.5.3</jandex-version>
         <jansi-version>2.4.3</jansi-version>
         <jasypt-version>1.9.3</jasypt-version>
-        <java-grok-version>0.1.9</java-grok-version>
+        <java-grok-version>0.1.2</java-grok-version>
         <java-util-version>4.102.0</java-util-version>
         <jnats-version>2.25.2</jnats-version>
         <javacc-maven-plugin-version>3.2.0</javacc-maven-plugin-version>