diff --git a/compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirDiagnosticsList.kt b/compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirDiagnosticsList.kt
index fc567b4169f..e15e023e68e 100644
--- a/compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirDiagnosticsList.kt
+++ b/compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirDiagnosticsList.kt
@@ -467,7 +467,7 @@ object DIAGNOSTICS_LIST : DiagnosticList("FirErrors") {
             parameter<KtModifierKeywordToken>("redundantModifier")
             parameter<KtModifierKeywordToken>("conflictingModifier")
         }
-        val DEPRECATED_MODIFIER by warning<PsiElement> {
+        val DEPRECATED_MODIFIER by error<PsiElement> {
             parameter<KtModifierKeywordToken>("deprecatedModifier")
             parameter<KtModifierKeywordToken>("actualModifier")
         }
diff --git a/compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/FirErrors.kt b/compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/FirErrors.kt
index 03efd783a91..4b70ab5bb5b 100644
--- a/compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/FirErrors.kt
+++ b/compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/FirErrors.kt
@@ -342,7 +342,7 @@ object FirErrors {
     val INAPPLICABLE_INFIX_MODIFIER: KtDiagnosticFactory0 by error0<PsiElement>(SourceElementPositioningStrategies.INFIX_MODIFIER)
     val REPEATED_MODIFIER: KtDiagnosticFactory1<KtModifierKeywordToken> by error1<PsiElement, KtModifierKeywordToken>()
     val REDUNDANT_MODIFIER: KtDiagnosticFactory2<KtModifierKeywordToken, KtModifierKeywordToken> by warning2<PsiElement, KtModifierKeywordToken, KtModifierKeywordToken>()
-    val DEPRECATED_MODIFIER: KtDiagnosticFactory2<KtModifierKeywordToken, KtModifierKeywordToken> by warning2<PsiElement, KtModifierKeywordToken, KtModifierKeywordToken>()
+    val DEPRECATED_MODIFIER: KtDiagnosticFactory2<KtModifierKeywordToken, KtModifierKeywordToken> by error2<PsiElement, KtModifierKeywordToken, KtModifierKeywordToken>()
     val DEPRECATED_MODIFIER_PAIR: KtDiagnosticFactory2<KtModifierKeywordToken, KtModifierKeywordToken> by warning2<PsiElement, KtModifierKeywordToken, KtModifierKeywordToken>()
     val DEPRECATED_MODIFIER_FOR_TARGET: KtDiagnosticFactory2<KtModifierKeywordToken, String> by warning2<PsiElement, KtModifierKeywordToken, String>()
     val REDUNDANT_MODIFIER_FOR_TARGET: KtDiagnosticFactory2<KtModifierKeywordToken, String> by warning2<PsiElement, KtModifierKeywordToken, String>()
diff --git a/compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/FirNonSuppressibleErrorNames.kt b/compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/FirNonSuppressibleErrorNames.kt
index a2d3305eb77..66af294e8a2 100644
--- a/compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/FirNonSuppressibleErrorNames.kt
+++ b/compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/FirNonSuppressibleErrorNames.kt
@@ -200,6 +200,7 @@ val FIR_NON_SUPPRESSIBLE_ERROR_NAMES: Set<String> = setOf(
     "EXPOSED_TYPE_PARAMETER_BOUND",
     "INAPPLICABLE_INFIX_MODIFIER",
     "REPEATED_MODIFIER",
+    "DEPRECATED_MODIFIER",
     "INCOMPATIBLE_MODIFIERS",
     "WRONG_MODIFIER_TARGET",
     "OPERATOR_MODIFIER_REQUIRED",
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 2d875f4ed21..0c1a22acb9b 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
@@ -133,7 +133,7 @@ object FirModifierChecker : FirBasicDeclarationChecker(MppCheckerKind.Common) {
             }
         }
 
-        val deprecatedModifierReplacement = deprecatedModifierMap[modifierToken]
+        val deprecatedModifierReplacement = deprecatedKmpModifierMap[modifierToken]
         if (deprecatedModifierReplacement != null) {
             reporter.reportOn(
                 modifierSource,
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/ModifiersChecker.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/ModifiersChecker.kt
index 66b1d6644db..ba0b0899dd9 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/ModifiersChecker.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/ModifiersChecker.kt
@@ -122,7 +122,7 @@ object ModifierCheckerCore {
             trace.report(Errors.WRONG_MODIFIER_TARGET.on(node.psi, modifier, actualTargets.firstOrNull()?.description ?: "this"))
             return false
         }
-        val deprecatedModifierReplacement = deprecatedModifierMap[modifier]
+        val deprecatedModifierReplacement = deprecatedKmpModifierMap[modifier]
         val deprecatedTargets = deprecatedTargetMap[modifier] ?: emptySet()
         val redundantTargets = redundantTargetMap[modifier] ?: emptySet()
         when {
diff --git a/compiler/psi/src/org/jetbrains/kotlin/resolve/ModifierCheckerHelpers.kt b/compiler/psi/src/org/jetbrains/kotlin/resolve/ModifierCheckerHelpers.kt
index 023f5fb6e6d..6fe13baa46e 100644
--- a/compiler/psi/src/org/jetbrains/kotlin/resolve/ModifierCheckerHelpers.kt
+++ b/compiler/psi/src/org/jetbrains/kotlin/resolve/ModifierCheckerHelpers.kt
@@ -288,7 +288,7 @@ val deprecatedTargetMap = mapOf<KtKeywordToken, Set<KotlinTarget>>()
 
 val deprecatedParentTargetMap = mapOf<KtKeywordToken, Set<KotlinTarget>>()
 
-val deprecatedModifierMap = mapOf(
+val deprecatedKmpModifierMap = mapOf(
     HEADER_KEYWORD to EXPECT_KEYWORD,
     IMPL_KEYWORD to ACTUAL_KEYWORD
 )