diff --git a/CODEOWNERS b/CODEOWNERS
index 9cbda824446..9ecca66238c 100644
--- a/CODEOWNERS
+++ b/CODEOWNERS
@@ -28,7 +28,6 @@
 /swift/extractor/ @github/codeql-swift @github/code-scanning-language-coverage
 /misc/codegen/ @github/codeql-swift
 /java/kotlin-extractor/ @github/codeql-kotlin @github/code-scanning-language-coverage
-/java/ql/test-kotlin1/ @github/codeql-kotlin
 /java/ql/test-kotlin2/ @github/codeql-kotlin
 
 # Experimental CodeQL cryptography
diff --git a/java/ql/integration-tests/kotlin/all-platforms/enhanced-nullability/test.py b/java/ql/integration-tests/kotlin/all-platforms/enhanced-nullability/test.py
index e6aa92cfc29..72ff061aa82 100644
--- a/java/ql/integration-tests/kotlin/all-platforms/enhanced-nullability/test.py
+++ b/java/ql/integration-tests/kotlin/all-platforms/enhanced-nullability/test.py
@@ -1,11 +1,11 @@
 import pathlib
 
 
-def test(codeql, java_full, kotlinc_2_3_20):
+def test(codeql, java_full):
     java_srcs = " ".join([str(s) for s in pathlib.Path().glob("*.java")])
     codeql.database.create(
         command=[
             f"javac {java_srcs} -d build",
-            "kotlinc -language-version 1.9 user.kt -cp build",
+            "kotlinc -language-version 2.0 user.kt -cp build",
         ]
     )
diff --git a/java/ql/integration-tests/kotlin/all-platforms/external-property-overloads/test.py b/java/ql/integration-tests/kotlin/all-platforms/external-property-overloads/test.py
index d21c0541cf4..338ae19a9aa 100644
--- a/java/ql/integration-tests/kotlin/all-platforms/external-property-overloads/test.py
+++ b/java/ql/integration-tests/kotlin/all-platforms/external-property-overloads/test.py
@@ -1,6 +1,6 @@
 import commands
 
 
-def test(codeql, java_full, kotlinc_2_3_20):
-    commands.run("kotlinc -language-version 1.9 test.kt -d lib")
-    codeql.database.create(command="kotlinc -language-version 1.9 user.kt -cp lib")
+def test(codeql, java_full):
+    commands.run("kotlinc -language-version 2.0 test.kt -d lib")
+    codeql.database.create(command="kotlinc -language-version 2.0 user.kt -cp lib")
diff --git a/java/ql/integration-tests/kotlin/all-platforms/extractor_information_kotlin1/ExtractorInformation.expected b/java/ql/integration-tests/kotlin/all-platforms/extractor_information_kotlin1/ExtractorInformation.expected
index 5e32cd7786e..d00ef5f0ec6 100644
--- a/java/ql/integration-tests/kotlin/all-platforms/extractor_information_kotlin1/ExtractorInformation.expected
+++ b/java/ql/integration-tests/kotlin/all-platforms/extractor_information_kotlin1/ExtractorInformation.expected
@@ -9,4 +9,4 @@
 | Percentage of calls with call target | 100 |
 | Total number of lines | 3 |
 | Total number of lines with extension kt | 3 |
-| Uses Kotlin 2: false | 1 |
+| Uses Kotlin 2: true | 1 |
diff --git a/java/ql/integration-tests/kotlin/all-platforms/extractor_information_kotlin1/test.py b/java/ql/integration-tests/kotlin/all-platforms/extractor_information_kotlin1/test.py
index eea3fcbf549..b5bb5378a23 100755
--- a/java/ql/integration-tests/kotlin/all-platforms/extractor_information_kotlin1/test.py
+++ b/java/ql/integration-tests/kotlin/all-platforms/extractor_information_kotlin1/test.py
@@ -1,2 +1,2 @@
-def test(codeql, java_full, kotlinc_2_3_20):
-    codeql.database.create(command=f"kotlinc -J-Xmx2G -language-version 1.9 SomeClass.kt")
+def test(codeql, java_full):
+    codeql.database.create(command="kotlinc -J-Xmx2G -language-version 2.0 SomeClass.kt")
diff --git a/java/ql/integration-tests/kotlin/all-platforms/file_classes/test.py b/java/ql/integration-tests/kotlin/all-platforms/file_classes/test.py
index baf7556962d..1d0913490f1 100644
--- a/java/ql/integration-tests/kotlin/all-platforms/file_classes/test.py
+++ b/java/ql/integration-tests/kotlin/all-platforms/file_classes/test.py
@@ -1,6 +1,6 @@
 import commands
 
 
-def test(codeql, java_full, kotlinc_2_3_20):
-    commands.run("kotlinc -language-version 1.9 A.kt")
-    codeql.database.create(command="kotlinc -cp . -language-version 1.9 B.kt C.kt")
+def test(codeql, java_full):
+    commands.run("kotlinc -language-version 2.0 A.kt")
+    codeql.database.create(command="kotlinc -cp . -language-version 2.0 B.kt C.kt")
diff --git a/java/ql/integration-tests/kotlin/all-platforms/java-interface-redeclares-tostring/test.py b/java/ql/integration-tests/kotlin/all-platforms/java-interface-redeclares-tostring/test.py
index 57b0b660561..1f24c2be790 100644
--- a/java/ql/integration-tests/kotlin/all-platforms/java-interface-redeclares-tostring/test.py
+++ b/java/ql/integration-tests/kotlin/all-platforms/java-interface-redeclares-tostring/test.py
@@ -1,6 +1,6 @@
 import commands
 
 
-def test(codeql, java_full, kotlinc_2_3_20):
+def test(codeql, java_full):
     commands.run(["javac", "Test.java", "-d", "bin"])
-    codeql.database.create(command="kotlinc -language-version 1.9 user.kt -cp bin")
+    codeql.database.create(command="kotlinc -language-version 2.0 user.kt -cp bin")
diff --git a/java/ql/integration-tests/kotlin/all-platforms/kotlin_java_lowering_wildcards/test.py b/java/ql/integration-tests/kotlin/all-platforms/kotlin_java_lowering_wildcards/test.py
index 6346892aaa7..b259450e7b9 100644
--- a/java/ql/integration-tests/kotlin/all-platforms/kotlin_java_lowering_wildcards/test.py
+++ b/java/ql/integration-tests/kotlin/all-platforms/kotlin_java_lowering_wildcards/test.py
@@ -1,13 +1,13 @@
 import commands
 
 
-def test(codeql, java_full, kotlinc_2_3_20):
+def test(codeql, java_full):
     # Compile the JavaDefns2 copy outside tracing, to make sure the Kotlin view of it matches the Java view seen by the traced javac compilation of JavaDefns.java below.
     commands.run(["javac", "JavaDefns2.java"])
     codeql.database.create(
         command=[
             "kotlinc kotlindefns.kt",
             "javac JavaUser.java JavaDefns.java -cp .",
-            "kotlinc -language-version 1.9 -cp . kotlinuser.kt",
+            "kotlinc -language-version 2.0 -cp . kotlinuser.kt",
         ]
     )