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 c9fdaff770e..54d1ab78ac6 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
@@ -276,7 +276,7 @@ object DIAGNOSTICS_LIST : DiagnosticList("FirErrors") {
             parameter<FqName>("optInMarkerFqName")
             parameter<String>("message")
         }
-        val OPT_IN_USAGE_ERROR by warning<PsiElement>(PositioningStrategy.REFERENCE_BY_QUALIFIED) {
+        val OPT_IN_USAGE_ERROR by error<PsiElement>(PositioningStrategy.REFERENCE_BY_QUALIFIED) {
             parameter<FqName>("optInMarkerFqName")
             parameter<String>("message")
         }
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 bc9b514fcb3..c166370f9fb 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
@@ -241,7 +241,7 @@ object FirErrors {
 
     // OptIn
     val OPT_IN_USAGE by warning2<PsiElement, FqName, String>(SourceElementPositioningStrategies.REFERENCE_BY_QUALIFIED)
-    val OPT_IN_USAGE_ERROR by warning2<PsiElement, FqName, String>(SourceElementPositioningStrategies.REFERENCE_BY_QUALIFIED)
+    val OPT_IN_USAGE_ERROR by error2<PsiElement, FqName, String>(SourceElementPositioningStrategies.REFERENCE_BY_QUALIFIED)
     val OPT_IN_OVERRIDE by warning2<PsiElement, FqName, String>()
     val OPT_IN_OVERRIDE_ERROR by error2<PsiElement, FqName, String>()
     val OPT_IN_IS_NOT_ENABLED by warning0<KtAnnotationEntry>(SourceElementPositioningStrategies.REFERENCED_NAME_BY_QUALIFIED)