diff --git a/compiler/fir/analysis-tests/testData/resolve/constVal/constValNotTopLevelOrObject.fir.txt b/compiler/fir/analysis-tests/testData/resolve/constVal/constValNotTopLevelOrObject.fir.txt
index 2d2712c64fc..e3dc4423ed9 100644
--- a/compiler/fir/analysis-tests/testData/resolve/constVal/constValNotTopLevelOrObject.fir.txt
+++ b/compiler/fir/analysis-tests/testData/resolve/constVal/constValNotTopLevelOrObject.fir.txt
@@ -11,10 +11,13 @@ FILE: constValNotTopLevelOrObject.kt
 
     }
     public final class C : R|kotlin/Any| {
-        public constructor(): R|C| {
+        public constructor(b: R|kotlin/Boolean|): R|C| {
             super<R|kotlin/Any|>()
         }
 
+        public final const val b: R|kotlin/Boolean| = R|<local>/b|
+            public get(): R|kotlin/Boolean|
+
         public final const val c: R|kotlin/Int| = Int(3)
             public get(): R|kotlin/Int|
 
diff --git a/compiler/fir/analysis-tests/testData/resolve/constVal/constValNotTopLevelOrObject.kt b/compiler/fir/analysis-tests/testData/resolve/constVal/constValNotTopLevelOrObject.kt
index 081508292d2..6a95133f9a6 100644
--- a/compiler/fir/analysis-tests/testData/resolve/constVal/constValNotTopLevelOrObject.kt
+++ b/compiler/fir/analysis-tests/testData/resolve/constVal/constValNotTopLevelOrObject.kt
@@ -4,7 +4,7 @@ object B {
     const val b = 2
 }
 
-class C {
+class C(<!CONST_VAL_NOT_TOP_LEVEL_OR_OBJECT!>const<!> val b: Boolean) {
     <!CONST_VAL_NOT_TOP_LEVEL_OR_OBJECT!>const<!> val c = 3
 }
 
diff --git a/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/fir/ValueParameter.kt b/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/fir/ValueParameter.kt
index 653140a46cf..031eba0172b 100644
--- a/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/fir/ValueParameter.kt
+++ b/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/fir/ValueParameter.kt
@@ -66,7 +66,7 @@ class ValueParameter(
                 this.isExpect = isExpect
                 isActual = modifiers.hasActual()
                 isOverride = modifiers.hasOverride()
-                isConst = false
+                isConst = modifiers.hasConst()
                 isLateInit = false
             }
             annotations += this@ValueParameter.firValueParameter.annotations
diff --git a/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/fir/modifier/Modifier.kt b/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/fir/modifier/Modifier.kt
index 0abdafe02b5..e8fcfed057f 100644
--- a/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/fir/modifier/Modifier.kt
+++ b/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/fir/modifier/Modifier.kt
@@ -19,6 +19,7 @@ import org.jetbrains.kotlin.fir.lightTree.fir.modifier.ModifierSets.PARAMETER_MO
 import org.jetbrains.kotlin.fir.lightTree.fir.modifier.ModifierSets.PLATFORM_MODIFIER
 import org.jetbrains.kotlin.fir.lightTree.fir.modifier.ModifierSets.PROPERTY_MODIFIER
 import org.jetbrains.kotlin.fir.lightTree.fir.modifier.ModifierSets.VISIBILITY_MODIFIER
+import org.jetbrains.kotlin.lexer.KtTokens
 
 class Modifier(
     private val classModifiers: MutableList<ClassModifier> = mutableListOf(),
@@ -34,23 +35,30 @@ class Modifier(
 
     fun addModifier(modifier: LighterASTNode, isInClass: Boolean = false) {
         val tokenType = modifier.tokenType
+        if (tokenType == KtTokens.CONST_KEYWORD) {
+            // Specific case because CONST may exist both on parameter and property
+            propertyModifier = PropertyModifier.CONST
+            parameterModifiers += ParameterModifier.CONST
+            return
+        }
+        val upperCasedModifier = modifier.toString().toUpperCase()
         when {
             INLINE_MODIFIER.contains(tokenType) -> {
                 if (isInClass)
-                    this.classModifiers += ClassModifier.valueOf(modifier.toString().toUpperCase())
+                    this.classModifiers += ClassModifier.valueOf(upperCasedModifier)
                 else
-                    this.functionModifiers += FunctionModifier.valueOf(modifier.toString().toUpperCase())
+                    this.functionModifiers += FunctionModifier.valueOf(upperCasedModifier)
             }
-            CLASS_MODIFIER.contains(tokenType) -> this.classModifiers += ClassModifier.valueOf(modifier.toString().toUpperCase())
-            MEMBER_MODIFIER.contains(tokenType) -> this.memberModifiers += MemberModifier.valueOf(modifier.toString().toUpperCase())
+            CLASS_MODIFIER.contains(tokenType) -> this.classModifiers += ClassModifier.valueOf(upperCasedModifier)
+            MEMBER_MODIFIER.contains(tokenType) -> this.memberModifiers += MemberModifier.valueOf(upperCasedModifier)
             VISIBILITY_MODIFIER.contains(tokenType) -> this.visibilityModifiers +=
-                VisibilityModifier.valueOf(modifier.toString().toUpperCase())
-            FUNCTION_MODIFIER.contains(tokenType) -> this.functionModifiers += FunctionModifier.valueOf(modifier.toString().toUpperCase())
-            PROPERTY_MODIFIER.contains(tokenType) -> this.propertyModifier = PropertyModifier.valueOf(modifier.toString().toUpperCase())
+                VisibilityModifier.valueOf(upperCasedModifier)
+            FUNCTION_MODIFIER.contains(tokenType) -> this.functionModifiers += FunctionModifier.valueOf(upperCasedModifier)
+            PROPERTY_MODIFIER.contains(tokenType) -> this.propertyModifier = PropertyModifier.valueOf(upperCasedModifier)
             INHERITANCE_MODIFIER.contains(tokenType) -> this.inheritanceModifiers +=
-                InheritanceModifier.valueOf(modifier.toString().toUpperCase())
-            PARAMETER_MODIFIER.contains(tokenType) -> this.parameterModifiers += ParameterModifier.valueOf(modifier.toString().toUpperCase())
-            PLATFORM_MODIFIER.contains(tokenType) -> this.platformModifiers += PlatformModifier.valueOf(modifier.toString().toUpperCase())
+                InheritanceModifier.valueOf(upperCasedModifier)
+            PARAMETER_MODIFIER.contains(tokenType) -> this.parameterModifiers += ParameterModifier.valueOf(upperCasedModifier)
+            PLATFORM_MODIFIER.contains(tokenType) -> this.platformModifiers += PlatformModifier.valueOf(upperCasedModifier)
         }
     }
 
@@ -167,4 +175,8 @@ class Modifier(
     fun hasActual(): Boolean {
         return platformModifiers.contains(PlatformModifier.ACTUAL) || platformModifiers.contains(PlatformModifier.IMPL)
     }
+
+    fun hasConst(): Boolean {
+        return parameterModifiers.contains(ParameterModifier.CONST)
+    }
 }
diff --git a/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/fir/modifier/ModifiersEnumSet.kt b/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/fir/modifier/ModifiersEnumSet.kt
index 779d27566d0..3700eaa1ef1 100644
--- a/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/fir/modifier/ModifiersEnumSet.kt
+++ b/compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/fir/modifier/ModifiersEnumSet.kt
@@ -51,7 +51,8 @@ enum class InheritanceModifier {
 enum class ParameterModifier {
     VARARG,
     NOINLINE,
-    CROSSINLINE
+    CROSSINLINE,
+    CONST
 }
 
 enum class PlatformModifier {
diff --git a/compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt b/compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt
index 1cb0e282638..4550ff88108 100644
--- a/compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt
+++ b/compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt
@@ -450,7 +450,7 @@ class RawFirBuilder(
                 this.isExpect = isExpect
                 isActual = hasActualModifier()
                 isOverride = hasModifier(OVERRIDE_KEYWORD)
-                isConst = false
+                isConst = hasModifier(CONST_KEYWORD)
                 isLateInit = false
             }
             val propertySource = toFirSourceElement(FirFakeSourceElementKind.PropertyFromParameter)
diff --git a/compiler/testData/diagnostics/tests/modifiers/const/applicability.fir.kt b/compiler/testData/diagnostics/tests/modifiers/const/applicability.fir.kt
index 28e7c7e45b6..1ef655c62fe 100644
--- a/compiler/testData/diagnostics/tests/modifiers/const/applicability.fir.kt
+++ b/compiler/testData/diagnostics/tests/modifiers/const/applicability.fir.kt
@@ -12,7 +12,7 @@ object A {
     const val inObject: Int = 4
 }
 
-class B(const val constructor: Int = 5)
+class B(<!CONST_VAL_NOT_TOP_LEVEL_OR_OBJECT!>const<!> val constructor: Int = 5)
 
 abstract class C {
     <!INCOMPATIBLE_MODIFIERS!>open<!> <!CONST_VAL_NOT_TOP_LEVEL_OR_OBJECT, INCOMPATIBLE_MODIFIERS!>const<!> val x: Int = 6