diff --git a/java/kotlin-extractor/src/main/kotlin/KotlinFileExtractor.kt b/java/kotlin-extractor/src/main/kotlin/KotlinFileExtractor.kt
index 0ca8cb4af09a..db73cace1ac8 100644
--- a/java/kotlin-extractor/src/main/kotlin/KotlinFileExtractor.kt
+++ b/java/kotlin-extractor/src/main/kotlin/KotlinFileExtractor.kt
@@ -27,30 +27,7 @@ import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.types.impl.makeTypeProjection
-import org.jetbrains.kotlin.ir.util.companionObject
-import org.jetbrains.kotlin.ir.util.constructors
-import org.jetbrains.kotlin.ir.util.fqNameWhenAvailable
-import org.jetbrains.kotlin.ir.util.hasAnnotation
-import org.jetbrains.kotlin.ir.util.hasInterfaceParent
-import org.jetbrains.kotlin.ir.util.isAnnotationClass
-import org.jetbrains.kotlin.ir.util.isAnonymousObject
-import org.jetbrains.kotlin.ir.util.isFakeOverride
-import org.jetbrains.kotlin.ir.util.isFunctionOrKFunction
-import org.jetbrains.kotlin.ir.util.isInterface
-import org.jetbrains.kotlin.ir.util.isLocal
-import org.jetbrains.kotlin.ir.util.isNonCompanionObject
-import org.jetbrains.kotlin.ir.util.isObject
-import org.jetbrains.kotlin.ir.util.isSuspend
-import org.jetbrains.kotlin.ir.util.isSuspendFunctionOrKFunction
-import org.jetbrains.kotlin.ir.util.isVararg
-import org.jetbrains.kotlin.ir.util.kotlinFqName
-import org.jetbrains.kotlin.ir.util.packageFqName
-import org.jetbrains.kotlin.ir.util.parentAsClass
-import org.jetbrains.kotlin.ir.util.parentClassOrNull
-import org.jetbrains.kotlin.ir.util.parents
-import org.jetbrains.kotlin.ir.util.primaryConstructor
-import org.jetbrains.kotlin.ir.util.render
-import org.jetbrains.kotlin.ir.util.target
+import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.load.java.JvmAnnotationNames
 import org.jetbrains.kotlin.load.java.NOT_NULL_ANNOTATIONS
 import org.jetbrains.kotlin.load.java.NULLABLE_ANNOTATIONS
@@ -826,7 +803,7 @@ open class KotlinFileExtractor(
         fun exprId() = tw.getLabelFor<DbExpr>("@\"annotationExpr;{$parent};$idx\"")
 
         return when (v) {
-            is IrConst<*> -> {
+            is CodeQLIrConst<*> -> {
                 extractConstant(v, parent, idx, null, null, overrideId = exprId())
             }
             is IrGetEnumValue -> {
@@ -5999,7 +5976,7 @@ open class KotlinFileExtractor(
                         extractExpressionExpr(a, callable, id, i, exprParent.enclosingStmt)
                     }
                 }
-                is IrConst<*> -> {
+                is CodeQLIrConst<*> -> {
                     val exprParent = parent.expr(e, callable)
                     extractConstant(
                         e,
@@ -6211,9 +6188,9 @@ open class KotlinFileExtractor(
                     if (
                         (isAndAnd || isOrOr) &&
                             e.branches.size == 2 &&
-                            (e.branches[1].condition as? IrConst<*>)?.value == true &&
+                            (e.branches[1].condition as? CodeQLIrConst<*>)?.value == true &&
                             (e.branches[if (e.origin == IrStatementOrigin.ANDAND) 1 else 0].result
-                                    as? IrConst<*>)
+                                    as? CodeQLIrConst<*>)
                                 ?.value == isOrOr
                     ) {
 
@@ -6869,7 +6846,7 @@ open class KotlinFileExtractor(
         }
 
     private fun extractConstant(
-        e: IrConst<*>,
+        e: CodeQLIrConst<*>,
         parent: Label<out DbExprparent>,
         idx: Int,
         enclosingCallable: Label<out DbCallable>?,
diff --git a/java/kotlin-extractor/src/main/kotlin/KotlinUsesExtractor.kt b/java/kotlin-extractor/src/main/kotlin/KotlinUsesExtractor.kt
index 3be94d65690f..be41c0ea70d0 100644
--- a/java/kotlin-extractor/src/main/kotlin/KotlinUsesExtractor.kt
+++ b/java/kotlin-extractor/src/main/kotlin/KotlinUsesExtractor.kt
@@ -5,7 +5,7 @@ import com.github.codeql.utils.versions.*
 import com.semmle.extractor.java.OdasaOutput
 import org.jetbrains.kotlin.backend.common.extensions.IrPluginContext
 import org.jetbrains.kotlin.backend.common.ir.*
-import org.jetbrains.kotlin.backend.jvm.ir.propertyIfAccessor
+import org.jetbrains.kotlin.backend.jvm.ir.*
 import org.jetbrains.kotlin.codegen.JvmCodegenUtil
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
@@ -24,6 +24,7 @@ import org.jetbrains.kotlin.load.kotlin.getJvmModuleNameForDeserializedDescripto
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.NameUtils
 import org.jetbrains.kotlin.name.SpecialNames
+import org.jetbrains.kotlin.resolve.descriptorUtil.propertyIfAccessor
 import org.jetbrains.kotlin.types.Variance
 import org.jetbrains.kotlin.util.OperatorNameConventions
 
@@ -84,7 +85,7 @@ open class KotlinUsesExtractor(
     }
 
     private fun extractFileClass(fqName: FqName): Label<out DbClassorinterface> {
-        val pkg = if (fqName.isRoot()) "" else fqName.parent().asString()
+        val pkg = if (fqName.codeQlIsRoot()) "" else fqName.parent().asString()
         val jvmName = fqName.shortName().asString()
         return extractFileClass(pkg, jvmName)
     }
@@ -906,7 +907,7 @@ open class KotlinUsesExtractor(
                 return arrayInfo.componentTypeResults
             }
             owner is IrClass -> {
-                val args = if (s.isRawType()) null else s.arguments
+                val args = if (s.codeQlIsRawType()) null else s.arguments
 
                 return useSimpleTypeClass(owner, args, s.isNullable())
             }
@@ -1232,9 +1233,10 @@ open class KotlinUsesExtractor(
     // false if it has `@JvmSuppressWildcards(false)`,
     // and null if the annotation is not present.
     @Suppress("UNCHECKED_CAST")
-    private fun getWildcardSuppressionDirective(t: IrAnnotationContainer) =
+    private fun getWildcardSuppressionDirective(t: IrAnnotationContainer): Boolean? =
         t.getAnnotation(jvmWildcardSuppressionAnnotation)?.let {
-            (it.getValueArgument(0) as? IrConst<Boolean>)?.value ?: true
+            @Suppress("USELESS_CAST") // `as? Boolean` is not needed for Kotlin < 2.1
+            (it.getValueArgument(0) as? CodeQLIrConst<Boolean>)?.value as? Boolean ?: true
         }
 
     private fun addJavaLoweringArgumentWildcards(
diff --git a/java/kotlin-extractor/src/main/kotlin/MetaAnnotationSupport.kt b/java/kotlin-extractor/src/main/kotlin/MetaAnnotationSupport.kt
index 2dc7382bf166..e591eed3eca6 100644
--- a/java/kotlin-extractor/src/main/kotlin/MetaAnnotationSupport.kt
+++ b/java/kotlin-extractor/src/main/kotlin/MetaAnnotationSupport.kt
@@ -27,13 +27,7 @@ import org.jetbrains.kotlin.ir.expressions.IrClassReference
 import org.jetbrains.kotlin.ir.expressions.IrConstructorCall
 import org.jetbrains.kotlin.ir.expressions.IrGetEnumValue
 import org.jetbrains.kotlin.ir.expressions.IrVararg
-import org.jetbrains.kotlin.ir.expressions.impl.IrClassReferenceImpl
-import org.jetbrains.kotlin.ir.expressions.impl.IrConstructorCallImpl
-import org.jetbrains.kotlin.ir.expressions.impl.IrGetEnumValueImpl
-import org.jetbrains.kotlin.ir.expressions.impl.IrGetFieldImpl
-import org.jetbrains.kotlin.ir.expressions.impl.IrGetValueImpl
-import org.jetbrains.kotlin.ir.expressions.impl.IrReturnImpl
-import org.jetbrains.kotlin.ir.expressions.impl.IrVarargImpl
+import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
 import org.jetbrains.kotlin.ir.types.typeWith
 import org.jetbrains.kotlin.ir.util.constructedClass
diff --git a/java/kotlin-extractor/src/main/kotlin/utils/JvmNames.kt b/java/kotlin-extractor/src/main/kotlin/utils/JvmNames.kt
index b6b51fde5430..ec7c17b39fc6 100644
--- a/java/kotlin-extractor/src/main/kotlin/utils/JvmNames.kt
+++ b/java/kotlin-extractor/src/main/kotlin/utils/JvmNames.kt
@@ -1,12 +1,12 @@
 package com.github.codeql.utils
 
 import com.github.codeql.utils.versions.allOverriddenIncludingSelf
+import com.github.codeql.utils.versions.CodeQLIrConst
 import org.jetbrains.kotlin.builtins.StandardNames
 import org.jetbrains.kotlin.ir.declarations.IrAnnotationContainer
 import org.jetbrains.kotlin.ir.declarations.IrClass
 import org.jetbrains.kotlin.ir.declarations.IrFunction
 import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
-import org.jetbrains.kotlin.ir.expressions.IrConst
 import org.jetbrains.kotlin.ir.expressions.IrConstructorCall
 import org.jetbrains.kotlin.ir.types.IrSimpleType
 import org.jetbrains.kotlin.ir.util.fqNameWhenAvailable
@@ -82,7 +82,7 @@ fun getJvmName(container: IrAnnotationContainer): String? {
             if (owner is IrClass) {
                 val aPkg = owner.packageFqName?.asString()
                 val name = owner.name.asString()
-                if (aPkg == "kotlin.jvm" && name == "JvmName" && v is IrConst<*>) {
+                if (aPkg == "kotlin.jvm" && name == "JvmName" && v is CodeQLIrConst<*>) {
                     val value = v.value
                     if (value is String) {
                         return value
diff --git a/java/kotlin-extractor/src/main/kotlin/utils/TypeSubstitution.kt b/java/kotlin-extractor/src/main/kotlin/utils/TypeSubstitution.kt
index 91cd5ec9f13d..6f8d0d33f373 100644
--- a/java/kotlin-extractor/src/main/kotlin/utils/TypeSubstitution.kt
+++ b/java/kotlin-extractor/src/main/kotlin/utils/TypeSubstitution.kt
@@ -15,7 +15,7 @@ import org.jetbrains.kotlin.ir.declarations.IrTypeParametersContainer
 import org.jetbrains.kotlin.ir.declarations.impl.IrExternalPackageFragmentImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrFactoryImpl
 import org.jetbrains.kotlin.ir.expressions.IrConstructorCall
-import org.jetbrains.kotlin.ir.expressions.impl.IrConstructorCallImpl
+import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.symbols.IrTypeParameterSymbol
 import org.jetbrains.kotlin.ir.symbols.impl.DescriptorlessExternalPackageFragmentSymbol
 import org.jetbrains.kotlin.ir.types.*
diff --git a/java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_5_0/CodeQLIrConst.kt b/java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_5_0/CodeQLIrConst.kt
new file mode 100644
index 000000000000..0f8f6bda71ae
--- /dev/null
+++ b/java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_5_0/CodeQLIrConst.kt
@@ -0,0 +1,5 @@
+package com.github.codeql.utils.versions
+
+import org.jetbrains.kotlin.ir.expressions.IrConst
+
+typealias CodeQLIrConst<T> = IrConst<T>
diff --git a/java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_5_0/CodeQLIsRoot.kt b/java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_5_0/CodeQLIsRoot.kt
new file mode 100644
index 000000000000..bf523ca88215
--- /dev/null
+++ b/java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_5_0/CodeQLIsRoot.kt
@@ -0,0 +1,5 @@
+package com.github.codeql.utils.versions
+
+import org.jetbrains.kotlin.name.FqName
+
+fun FqName.codeQlIsRoot() = this.isRoot()
diff --git a/java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_5_0/Types.kt b/java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_5_0/Types.kt
index 630d649907ca..61a580e2a279 100644
--- a/java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_5_0/Types.kt
+++ b/java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_5_0/Types.kt
@@ -3,4 +3,4 @@ package com.github.codeql.utils.versions
 import org.jetbrains.kotlin.backend.jvm.codegen.isRawType
 import org.jetbrains.kotlin.ir.types.IrSimpleType
 
-fun IrSimpleType.isRawType() = this.isRawType()
+fun IrSimpleType.codeQlIsRawType() = this.isRawType()
diff --git a/java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_6_20/Types.kt b/java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_6_20/Types.kt
index d44e44074005..7db5d520b29f 100644
--- a/java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_6_20/Types.kt
+++ b/java/kotlin-extractor/src/main/kotlin/utils/versions/v_1_6_20/Types.kt
@@ -3,4 +3,4 @@ package com.github.codeql.utils.versions
 import org.jetbrains.kotlin.backend.jvm.ir.isRawType
 import org.jetbrains.kotlin.ir.types.IrSimpleType
 
-fun IrSimpleType.isRawType() = this.isRawType()
+fun IrSimpleType.codeQlIsRawType() = this.isRawType()
diff --git a/java/kotlin-extractor/src/main/kotlin/utils/versions/v_2_1_0-Beta1/CodeQLIrConst.kt b/java/kotlin-extractor/src/main/kotlin/utils/versions/v_2_1_0-Beta1/CodeQLIrConst.kt
new file mode 100644
index 000000000000..60ff588cd97f
--- /dev/null
+++ b/java/kotlin-extractor/src/main/kotlin/utils/versions/v_2_1_0-Beta1/CodeQLIrConst.kt
@@ -0,0 +1,5 @@
+package com.github.codeql.utils.versions
+
+import org.jetbrains.kotlin.ir.expressions.IrConst
+
+typealias CodeQLIrConst<T> = IrConst
diff --git a/java/kotlin-extractor/src/main/kotlin/utils/versions/v_2_1_0-Beta1/CodeQLIsRoot.kt b/java/kotlin-extractor/src/main/kotlin/utils/versions/v_2_1_0-Beta1/CodeQLIsRoot.kt
new file mode 100644
index 000000000000..e8eff805f21a
--- /dev/null
+++ b/java/kotlin-extractor/src/main/kotlin/utils/versions/v_2_1_0-Beta1/CodeQLIsRoot.kt
@@ -0,0 +1,5 @@
+package com.github.codeql.utils.versions
+
+import org.jetbrains.kotlin.name.FqName
+
+fun FqName.codeQlIsRoot() = this.isRoot