diff --git a/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDataClassConverters.kt b/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDataClassConverters.kt
index f1eab260ebd..bc4ab5692f9 100644
--- a/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDataClassConverters.kt
+++ b/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDataClassConverters.kt
@@ -4919,12 +4919,6 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             token,
         )
     }
-    add(FirJvmErrors.CONFLICTING_JVM_DECLARATIONS) { firDiagnostic ->
-        ConflictingJvmDeclarationsImpl(
-            firDiagnostic as KtPsiDiagnostic,
-            token,
-        )
-    }
     add(FirJvmErrors.OVERRIDE_CANNOT_BE_STATIC) { firDiagnostic ->
         OverrideCannotBeStaticImpl(
             firDiagnostic as KtPsiDiagnostic,
diff --git a/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnostics.kt b/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnostics.kt
index 63e79d0764f..eb01e588aab 100644
--- a/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnostics.kt
+++ b/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnostics.kt
@@ -3425,10 +3425,6 @@ sealed interface KtFirDiagnostic<PSI : PsiElement> : KtDiagnosticWithPsi<PSI> {
         val presentableString: String
     }
 
-    interface ConflictingJvmDeclarations : KtFirDiagnostic<PsiElement> {
-        override val diagnosticClass get() = ConflictingJvmDeclarations::class
-    }
-
     interface OverrideCannotBeStatic : KtFirDiagnostic<PsiElement> {
         override val diagnosticClass get() = OverrideCannotBeStatic::class
     }
diff --git a/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnosticsImpl.kt b/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnosticsImpl.kt
index 574fe8bef74..c62183ed798 100644
--- a/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnosticsImpl.kt
+++ b/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnosticsImpl.kt
@@ -4130,11 +4130,6 @@ internal class PreReleaseClassImpl(
     token: KtLifetimeToken,
 ) : KtAbstractFirDiagnostic<PsiElement>(firDiagnostic, token), KtFirDiagnostic.PreReleaseClass
 
-internal class ConflictingJvmDeclarationsImpl(
-    firDiagnostic: KtPsiDiagnostic,
-    token: KtLifetimeToken,
-) : KtAbstractFirDiagnostic<PsiElement>(firDiagnostic, token), KtFirDiagnostic.ConflictingJvmDeclarations
-
 internal class OverrideCannotBeStaticImpl(
     firDiagnostic: KtPsiDiagnostic,
     token: KtLifetimeToken,
diff --git a/compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirJvmDiagnosticsList.kt b/compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirJvmDiagnosticsList.kt
index 857dabe41ee..ed4336320cd 100644
--- a/compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirJvmDiagnosticsList.kt
+++ b/compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirJvmDiagnosticsList.kt
@@ -24,8 +24,6 @@ import org.jetbrains.kotlin.util.PrivateForInline
 @OptIn(PrivateForInline::class)
 object JVM_DIAGNOSTICS_LIST : DiagnosticList("FirJvmErrors") {
     val DECLARATIONS by object : DiagnosticGroup("Declarations") {
-        val CONFLICTING_JVM_DECLARATIONS by error<PsiElement>()
-
         val OVERRIDE_CANNOT_BE_STATIC by error<PsiElement>()
         val JVM_STATIC_NOT_IN_OBJECT_OR_CLASS_COMPANION by error<PsiElement>(PositioningStrategy.DECLARATION_SIGNATURE)
         val JVM_STATIC_NOT_IN_OBJECT_OR_COMPANION by error<PsiElement>(PositioningStrategy.DECLARATION_SIGNATURE)
diff --git a/compiler/fir/checkers/checkers.jvm/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/jvm/FirJvmErrors.kt b/compiler/fir/checkers/checkers.jvm/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/jvm/FirJvmErrors.kt
index be8e980a936..2920f2706ab 100644
--- a/compiler/fir/checkers/checkers.jvm/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/jvm/FirJvmErrors.kt
+++ b/compiler/fir/checkers/checkers.jvm/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/jvm/FirJvmErrors.kt
@@ -32,7 +32,6 @@ import org.jetbrains.kotlin.psi.KtExpression
 
 object FirJvmErrors {
     // Declarations
-    val CONFLICTING_JVM_DECLARATIONS by error0<PsiElement>()
     val OVERRIDE_CANNOT_BE_STATIC by error0<PsiElement>()
     val JVM_STATIC_NOT_IN_OBJECT_OR_CLASS_COMPANION by error0<PsiElement>(SourceElementPositioningStrategies.DECLARATION_SIGNATURE)
     val JVM_STATIC_NOT_IN_OBJECT_OR_COMPANION by error0<PsiElement>(SourceElementPositioningStrategies.DECLARATION_SIGNATURE)
diff --git a/compiler/fir/checkers/checkers.jvm/src/org/jetbrains/kotlin/fir/analysis/diagnostics/jvm/FirJvmErrorsDefaultMessages.kt b/compiler/fir/checkers/checkers.jvm/src/org/jetbrains/kotlin/fir/analysis/diagnostics/jvm/FirJvmErrorsDefaultMessages.kt
index 4bac1ecb76e..0cbaf2b05bb 100644
--- a/compiler/fir/checkers/checkers.jvm/src/org/jetbrains/kotlin/fir/analysis/diagnostics/jvm/FirJvmErrorsDefaultMessages.kt
+++ b/compiler/fir/checkers/checkers.jvm/src/org/jetbrains/kotlin/fir/analysis/diagnostics/jvm/FirJvmErrorsDefaultMessages.kt
@@ -5,16 +5,13 @@
 
 package org.jetbrains.kotlin.fir.analysis.diagnostics.jvm
 
-import com.intellij.openapi.util.io.FileUtil
 import org.jetbrains.kotlin.diagnostics.KtDiagnosticFactoryToRendererMap
 import org.jetbrains.kotlin.diagnostics.KtDiagnosticRenderers.TO_STRING
 import org.jetbrains.kotlin.diagnostics.rendering.BaseDiagnosticRendererFactory
 import org.jetbrains.kotlin.diagnostics.rendering.CommonRenderers.STRING
-import org.jetbrains.kotlin.diagnostics.rendering.Renderer
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirDiagnosticRenderers.DECLARATION_NAME
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirDiagnosticRenderers.RENDER_TYPE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.jvm.FirJvmErrors.CONCURRENT_HASH_MAP_CONTAINS_OPERATOR
-import org.jetbrains.kotlin.fir.analysis.diagnostics.jvm.FirJvmErrors.CONFLICTING_JVM_DECLARATIONS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.jvm.FirJvmErrors.DELEGATION_BY_IN_JVM_RECORD
 import org.jetbrains.kotlin.fir.analysis.diagnostics.jvm.FirJvmErrors.DEPRECATED_JAVA_ANNOTATION
 import org.jetbrains.kotlin.fir.analysis.diagnostics.jvm.FirJvmErrors.ENUM_JVM_RECORD
@@ -84,7 +81,6 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.jvm.FirJvmErrors.VALUE_CLAS
 object FirJvmErrorsDefaultMessages : BaseDiagnosticRendererFactory() {
 
     override val MAP = KtDiagnosticFactoryToRendererMap("FIR").also { map ->
-        map.put(CONFLICTING_JVM_DECLARATIONS, "Platform declaration clash.")
         map.put(JAVA_TYPE_MISMATCH, "Java type mismatch: expected ''{0}'' but found ''{1}''. Use explicit cast.", RENDER_TYPE, RENDER_TYPE)
         map.put(UPPER_BOUND_CANNOT_BE_ARRAY, "Upper bound of type parameter cannot be an array.")
         map.put(STRICTFP_ON_CLASS, "'@Strictfp' annotation on classes is not yet supported.")
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 db2bb92a1d0..8ec80bbf5b1 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
@@ -568,7 +568,6 @@ val FIR_NON_SUPPRESSIBLE_ERROR_NAMES: Set<String> = setOf(
     "MIXING_FUNCTIONAL_KINDS_IN_SUPERTYPES",
     "INCOMPATIBLE_CLASS",
     "PRE_RELEASE_CLASS",
-    "CONFLICTING_JVM_DECLARATIONS",
     "OVERRIDE_CANNOT_BE_STATIC",
     "JVM_STATIC_NOT_IN_OBJECT_OR_CLASS_COMPANION",
     "JVM_STATIC_NOT_IN_OBJECT_OR_COMPANION",
diff --git a/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/JvmBackendErrors.kt b/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/JvmBackendErrors.kt
index 865639a7e8d..8fd7818acbf 100644
--- a/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/JvmBackendErrors.kt
+++ b/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/JvmBackendErrors.kt
@@ -19,7 +19,6 @@ import org.jetbrains.kotlin.resolve.MemberComparator
 import org.jetbrains.kotlin.utils.join
 
 object JvmBackendErrors {
-    // TODO: slightly different errors of this type exist also in fir checkers, consider unifying
     val CONFLICTING_JVM_DECLARATIONS by error1<PsiElement, ConflictingJvmDeclarationsData>(DECLARATION_SIGNATURE_OR_DEFAULT)
     val CONFLICTING_INHERITED_JVM_DECLARATIONS by error1<PsiElement, ConflictingJvmDeclarationsData>(DECLARATION_SIGNATURE_OR_DEFAULT)
     val ACCIDENTAL_OVERRIDE by error1<PsiElement, ConflictingJvmDeclarationsData>(DECLARATION_SIGNATURE_OR_DEFAULT)