diff --git a/x-pack/plugin/esql/src/internalClusterTest/java/org/elasticsearch/xpack/esql/plugin/KqlFunctionIT.java b/x-pack/plugin/esql/src/internalClusterTest/java/org/elasticsearch/xpack/esql/plugin/KqlFunctionIT.java
index 43c779794f3fc..d58637ab52c86 100644
--- a/x-pack/plugin/esql/src/internalClusterTest/java/org/elasticsearch/xpack/esql/plugin/KqlFunctionIT.java
+++ b/x-pack/plugin/esql/src/internalClusterTest/java/org/elasticsearch/xpack/esql/plugin/KqlFunctionIT.java
@@ -14,9 +14,8 @@
 import org.elasticsearch.xpack.esql.VerificationException;
 import org.elasticsearch.xpack.esql.action.AbstractEsqlIntegTestCase;
 import org.elasticsearch.xpack.esql.action.EsqlCapabilities;
-import org.elasticsearch.xpack.esql.action.EsqlQueryRequest;
-import org.elasticsearch.xpack.esql.action.EsqlQueryResponse;
 import org.junit.Before;
+import org.junit.BeforeClass;
 
 import java.util.List;
 
@@ -25,17 +24,16 @@
 
 public class KqlFunctionIT extends AbstractEsqlIntegTestCase {
 
+    @BeforeClass
+    protected static void ensureKqlFunctionEnabled() {
+        assumeTrue("kql function capability not available", EsqlCapabilities.Cap.KQL_FUNCTION.isEnabled());
+    }
+
     @Before
     public void setupIndex() {
         createAndPopulateIndex();
     }
 
-    @Override
-    protected EsqlQueryResponse run(EsqlQueryRequest request) {
-        assumeTrue("kql function capability not available", EsqlCapabilities.Cap.KQL_FUNCTION.isEnabled());
-        return super.run(request);
-    }
-
     public void testSimpleKqlQuery() {
         var query = """
             FROM test
diff --git a/x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/analysis/VerifierTests.java b/x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/analysis/VerifierTests.java
index 144d4ec9579f0..c1604bb5f5d06 100644
--- a/x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/analysis/VerifierTests.java
+++ b/x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/analysis/VerifierTests.java
@@ -1262,6 +1262,9 @@ public void testQueryStringFunctionsNotAllowedAfterCommands() throws Exception {
     }
 
     public void testKqlFunctionsNotAllowedAfterCommands() throws Exception {
+        // Skip test if the kql function is not enabled.
+        assumeTrue("kql function capability not available", EsqlCapabilities.Cap.KQL_FUNCTION.isEnabled());
+
         // Source commands
         assertEquals("1:13: [KQL] function cannot be used after SHOW", error("show info | where kql(\"8.16.0\")"));
         assertEquals("1:17: [KQL] function cannot be used after ROW", error("row a= \"Anna\" | where kql(\"Anna\")"));
@@ -1319,6 +1322,9 @@ public void testQueryStringFunctionOnlyAllowedInWhere() throws Exception {
     }
 
     public void testKqlFunctionOnlyAllowedInWhere() throws Exception {
+        // Skip test if the kql function is not enabled.
+        assumeTrue("kql function capability not available", EsqlCapabilities.Cap.KQL_FUNCTION.isEnabled());
+
         assertEquals("1:9: [KQL] function is only supported in WHERE commands", error("row a = kql(\"Anna\")"));
         checkFullTextFunctionsOnlyAllowedInWhere("KQL", "kql(\"Anna\")", "function");
     }
@@ -1366,6 +1372,9 @@ public void testQueryStringFunctionArgNotNullOrConstant() throws Exception {
     }
 
     public void testKqlFunctionArgNotNullOrConstant() throws Exception {
+        // Skip test if the kql function is not enabled.
+        assumeTrue("kql function capability not available", EsqlCapabilities.Cap.KQL_FUNCTION.isEnabled());
+
         assertEquals(
             "1:19: argument of [kql(first_name)] must be a constant, received [first_name]",
             error("from test | where kql(first_name)")
@@ -1379,6 +1388,9 @@ public void testQueryStringWithDisjunctions() {
     }
 
     public void testKqlFunctionWithDisjunctions() {
+        // Skip test if the kql function is not enabled.
+        assumeTrue("kql function capability not available", EsqlCapabilities.Cap.KQL_FUNCTION.isEnabled());
+
         checkWithDisjunctions("KQL", "kql(\"first_name: Anna\")", "function");
     }
 
@@ -1440,6 +1452,9 @@ public void testQueryStringFunctionWithNonBooleanFunctions() {
     }
 
     public void testKqlFunctionWithNonBooleanFunctions() {
+        // Skip test if the kql function is not enabled.
+        assumeTrue("kql function capability not available", EsqlCapabilities.Cap.KQL_FUNCTION.isEnabled());
+
         checkFullTextFunctionsWithNonBooleanFunctions("KQL", "kql(\"first_name: Anna\")", "function");
     }
 
diff --git a/x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/expression/function/fulltext/KqlTests.java b/x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/expression/function/fulltext/KqlTests.java
index 59d144d9d6d36..ccd05a08624f1 100644
--- a/x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/expression/function/fulltext/KqlTests.java
+++ b/x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/expression/function/fulltext/KqlTests.java
@@ -11,6 +11,7 @@
 import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
 
 import org.apache.lucene.util.BytesRef;
+import org.elasticsearch.xpack.esql.action.EsqlCapabilities;
 import org.elasticsearch.xpack.esql.core.expression.Expression;
 import org.elasticsearch.xpack.esql.core.tree.Source;
 import org.elasticsearch.xpack.esql.core.type.DataType;
@@ -18,6 +19,7 @@
 import org.elasticsearch.xpack.esql.expression.function.FunctionName;
 import org.elasticsearch.xpack.esql.expression.function.TestCaseSupplier;
 import org.hamcrest.Matcher;
+import org.junit.BeforeClass;
 
 import java.util.LinkedList;
 import java.util.List;
@@ -27,6 +29,10 @@
 
 @FunctionName("kql")
 public class KqlTests extends AbstractFunctionTestCase {
+    @BeforeClass
+    protected static void ensureKqlFunctionEnabled() {
+        assumeTrue("kql function capability not available", EsqlCapabilities.Cap.KQL_FUNCTION.isEnabled());
+    }
 
     public KqlTests(@Name("TestCase") Supplier<TestCaseSupplier.TestCase> testCaseSupplier) {
         this.testCase = testCaseSupplier.get();
diff --git a/x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/optimizer/LocalPhysicalPlanOptimizerTests.java b/x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/optimizer/LocalPhysicalPlanOptimizerTests.java
index 018a0166a19dd..0d0d78f81ffef 100644
--- a/x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/optimizer/LocalPhysicalPlanOptimizerTests.java
+++ b/x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/optimizer/LocalPhysicalPlanOptimizerTests.java
@@ -711,6 +711,9 @@ public void testMatchFunctionMultipleMatchClauses() {
      *       \_EsQueryExec[test], indexMode[standard], query[{"kql":{"query":"last_name: Smith"}}]
      */
     public void testKqlFunction() {
+        // Skip test if the kql function is not enabled.
+        assumeTrue("kql function capability not available", EsqlCapabilities.Cap.KQL_FUNCTION.isEnabled());
+
         var plan = plannerOptimizer.plan("""
             from test
             | where kql("last_name: Smith")
@@ -739,6 +742,9 @@ public void testKqlFunction() {
      *        "boost":1.0}}][_doc{f}#1423], limit[1000], sort[] estimatedRowSize[324]
      */
     public void testKqlFunctionConjunctionWhereOperands() {
+        // Skip test if the kql function is not enabled.
+        assumeTrue("kql function capability not available", EsqlCapabilities.Cap.KQL_FUNCTION.isEnabled());
+
         String queryText = """
             from test
             | where kql("last_name: Smith") and emp_no > 10010
@@ -773,6 +779,9 @@ public void testKqlFunctionConjunctionWhereOperands() {
      *       "source":"cidr_match(ip, \"127.0.0.1/32\")@2:38"}}],"boost":1.0}}][_doc{f}#21], limit[1000], sort[] estimatedRowSize[354]
      */
     public void testKqlFunctionWithFunctionsPushedToLucene() {
+        // Skip test if the kql function is not enabled.
+        assumeTrue("kql function capability not available", EsqlCapabilities.Cap.KQL_FUNCTION.isEnabled());
+
         String queryText = """
             from test
             | where kql("last_name: Smith") and cidr_match(ip, "127.0.0.1/32")
@@ -808,6 +817,9 @@ public void testKqlFunctionWithFunctionsPushedToLucene() {
      *       "boost":1.0}}][_doc{f}#1167], limit[1000], sort[] estimatedRowSize[324]
      */
     public void testKqlFunctionMultipleWhereClauses() {
+        // Skip test if the kql function is not enabled.
+        assumeTrue("kql function capability not available", EsqlCapabilities.Cap.KQL_FUNCTION.isEnabled());
+
         String queryText = """
             from test
             | where kql("last_name: Smith")
@@ -842,6 +854,9 @@ public void testKqlFunctionMultipleWhereClauses() {
      *       {"kql":{"query":"emp_no > 10010"}}],"boost":1.0}}]
      */
     public void testKqlFunctionMultipleKqlClauses() {
+        // Skip test if the kql function is not enabled.
+        assumeTrue("kql function capability not available", EsqlCapabilities.Cap.KQL_FUNCTION.isEnabled());
+
         String queryText = """
             from test
             | where kql("last_name: Smith") and kql("emp_no > 10010")