diff --git a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirModifierList.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/FirModifierList.kt
similarity index 78%
rename from compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirModifierList.kt
rename to compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/FirModifierList.kt
index c9e42fd1d38..56b49588641 100644
--- a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirModifierList.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/FirModifierList.kt
@@ -3,7 +3,7 @@
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package org.jetbrains.kotlin.fir
+package org.jetbrains.kotlin.fir.analysis.checkers
 
 import com.intellij.lang.ASTNode
 import com.intellij.lang.LighterASTNode
@@ -11,14 +11,30 @@ import com.intellij.openapi.util.Ref
 import com.intellij.psi.PsiElement
 import com.intellij.psi.tree.TokenSet
 import com.intellij.util.diff.FlyweightCapableTreeStructure
+import org.jetbrains.kotlin.KtNodeTypes
+import org.jetbrains.kotlin.fir.*
 import org.jetbrains.kotlin.lexer.KtModifierKeywordToken
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.KtModifierList
+import org.jetbrains.kotlin.psi.KtModifierListOwner
 
 sealed class FirModifierList {
     abstract val modifiers: List<FirModifier<*>>
 }
 
+fun FirSourceElement?.getModifierList(): FirModifierList? {
+    return when (this) {
+        null -> null
+        is FirPsiSourceElement<*> -> (psi as? KtModifierListOwner)?.modifierList?.let { FirPsiModifierList(it) }
+        is FirLightSourceElement -> {
+            val kidsRef = Ref<Array<LighterASTNode?>>()
+            tree.getChildren(element, kidsRef)
+            val modifierListNode = kidsRef.get().find { it?.tokenType == KtNodeTypes.MODIFIER_LIST } ?: return null
+            FirLightModifierList(modifierListNode, tree)
+        }
+    }
+}
+
 private val MODIFIER_KEYWORD_SET = TokenSet.orSet(KtTokens.SOFT_KEYWORDS, TokenSet.create(KtTokens.IN_KEYWORD, KtTokens.FUN_KEYWORD))
 
 class FirPsiModifierList(val modifierList: KtModifierList) : FirModifierList() {
@@ -67,4 +83,4 @@ val FirModifier<*>.source: FirSourceElement?
             val endOffset = tree.getEndOffset(node)
             node.toFirLightSourceElement(startOffset, endOffset, tree)
         }
-    }
\ No newline at end of file
+    }
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierChecker.kt
index 0c278237b24..6df15a0805c 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierChecker.kt
@@ -6,11 +6,18 @@
 package org.jetbrains.kotlin.fir.analysis.checkers.declaration
 
 import org.jetbrains.kotlin.KtNodeTypes
-import org.jetbrains.kotlin.fir.*
+import org.jetbrains.kotlin.fir.FirSourceElement
+import org.jetbrains.kotlin.fir.analysis.checkers.FirModifier
+import org.jetbrains.kotlin.fir.analysis.checkers.FirModifierList
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.getModifierList
+import org.jetbrains.kotlin.fir.analysis.checkers.source
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
-import org.jetbrains.kotlin.fir.declarations.*
+import org.jetbrains.kotlin.fir.declarations.FirClass
+import org.jetbrains.kotlin.fir.declarations.FirDeclaration
+import org.jetbrains.kotlin.fir.declarations.FirProperty
+import org.jetbrains.kotlin.fir.declarations.FirValueParameter
 import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertyAccessor
 import org.jetbrains.kotlin.lexer.KtModifierKeywordToken
 import org.jetbrains.kotlin.lexer.KtTokens.*
@@ -195,5 +202,4 @@ object FirModifierChecker : FirDeclarationChecker<FirDeclaration>() {
         val source = modifier.source
         source?.let { report(FirErrors.INCOMPATIBLE_MODIFIERS.on(it, firstKeyword, secondKeyword)) }
     }
-
-}
\ No newline at end of file
+}
diff --git a/compiler/fir/tree/build.gradle.kts b/compiler/fir/tree/build.gradle.kts
index 2f6f6a580ba..43aa2ee46dc 100644
--- a/compiler/fir/tree/build.gradle.kts
+++ b/compiler/fir/tree/build.gradle.kts
@@ -6,7 +6,6 @@ plugins {
 }
 
 dependencies {
-    compile(project(":compiler:psi"))
     compile(project(":compiler:frontend.common"))
     compile(project(":core:descriptors"))
     compile(project(":compiler:fir:cones"))
diff --git a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirSourceElement.kt b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirSourceElement.kt
index bc44b0ed2de..760094f48f0 100644
--- a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirSourceElement.kt
+++ b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirSourceElement.kt
@@ -6,14 +6,9 @@
 package org.jetbrains.kotlin.fir
 
 import com.intellij.lang.LighterASTNode
-import com.intellij.openapi.util.Ref
 import com.intellij.psi.PsiElement
 import com.intellij.psi.tree.IElementType
 import com.intellij.util.diff.FlyweightCapableTreeStructure
-import org.jetbrains.kotlin.KtNodeTypes
-import org.jetbrains.kotlin.psi.KtModifierListOwner
-import org.jetbrains.kotlin.psi.psiUtil.endOffset
-import org.jetbrains.kotlin.psi.psiUtil.startOffset
 
 sealed class FirSourceElement {
     abstract val elementType: IElementType
@@ -26,10 +21,10 @@ class FirPsiSourceElement<P : PsiElement>(val psi: P) : FirSourceElement() {
         get() = psi.node.elementType
 
     override val startOffset: Int
-        get() = psi.startOffset
+        get() = psi.textRange.startOffset
 
     override val endOffset: Int
-        get() = psi.endOffset
+        get() = psi.textRange.endOffset
 }
 
 class FirLightSourceElement(
@@ -56,16 +51,3 @@ inline fun LighterASTNode.toFirLightSourceElement(
 ): FirLightSourceElement = FirLightSourceElement(this, startOffset, endOffset, tree)
 
 val FirSourceElement?.lightNode: LighterASTNode? get() = (this as? FirLightSourceElement)?.element
-
-fun FirSourceElement?.getModifierList(): FirModifierList? {
-    return when (this) {
-        null -> null
-        is FirPsiSourceElement<*> -> (psi as? KtModifierListOwner)?.modifierList?.let { FirPsiModifierList(it) }
-        is FirLightSourceElement -> {
-            val kidsRef = Ref<Array<LighterASTNode?>>()
-            tree.getChildren(element, kidsRef)
-            val modifierListNode = kidsRef.get().find { it?.tokenType == KtNodeTypes.MODIFIER_LIST } ?: return null
-            FirLightModifierList(modifierListNode, tree)
-        }
-    }
-}