diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirExhaustiveWhenChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirExhaustiveWhenChecker.kt
index 163161fd572ee..49ec5d0b03726 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirExhaustiveWhenChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirExhaustiveWhenChecker.kt
@@ -12,8 +12,10 @@ import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.diagnostics.WhenMissingCase
 import org.jetbrains.kotlin.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.FirModuleData
 import org.jetbrains.kotlin.fir.analysis.checkers.MppCheckerKind
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.fullyExpandedClassId
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
 import org.jetbrains.kotlin.fir.declarations.utils.isEnumClass
 import org.jetbrains.kotlin.fir.declarations.utils.isExpect
@@ -22,8 +24,12 @@ import org.jetbrains.kotlin.fir.expressions.ExhaustivenessStatus
 import org.jetbrains.kotlin.fir.expressions.FirWhenExpression
 import org.jetbrains.kotlin.fir.expressions.impl.FirElseIfTrueCondition
 import org.jetbrains.kotlin.fir.expressions.impl.FirEmptyExpressionBlock
+import org.jetbrains.kotlin.fir.moduleData
+import org.jetbrains.kotlin.fir.resolve.providers.symbolProvider
 import org.jetbrains.kotlin.fir.resolve.toRegularClassSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirRegularClassSymbol
+import org.jetbrains.kotlin.fir.types.ConeKotlinType
+import org.jetbrains.kotlin.fir.types.coneType
 import org.jetbrains.kotlin.fir.types.isBooleanOrNullableBoolean
 
 object FirExhaustiveWhenChecker : FirWhenExpressionChecker(MppCheckerKind.Common) {
@@ -125,11 +131,24 @@ object FirExhaustiveWhenChecker : FirWhenExpressionChecker(MppCheckerKind.Common
         if (whenExpression.exhaustivenessStatus == ExhaustivenessStatus.RedundantlyExhaustive) {
             for (branch in whenExpression.branches) {
                 if (branch.source == null || branch.condition !is FirElseIfTrueCondition) continue
-                reporter.reportOn(branch.source, FirErrors.REDUNDANT_ELSE_IN_WHEN)
+
+                val subjectConeType = whenExpression.subjectVariable?.returnTypeRef?.coneType
+                if (subjectConeType == null ||
+                    subjectConeType.isBooleanOrNullableBoolean || // Values are known
+                    subjectConeType.getModuleDataOrNull() == context.session.moduleData // Subject is from the same module
+                ) {
+                    reporter.reportOn(branch.source, FirErrors.REDUNDANT_ELSE_IN_WHEN)
+                }
             }
         }
     }
 
+    context(context: CheckerContext)
+    private fun ConeKotlinType.getModuleDataOrNull(): FirModuleData? {
+        val classId = fullyExpandedClassId(context.session) ?: return null
+        return context.session.symbolProvider.getClassLikeSymbolByClassId(classId)?.moduleData
+    }
+
     private val KtSourceElement.isIfExpression: Boolean
         get() = elementType == KtNodeTypes.IF
 
diff --git a/compiler/testData/diagnostics/tests/multimodule/redundantElseInWhen.fir.kt b/compiler/testData/diagnostics/tests/multimodule/redundantElseInWhen.fir.kt
deleted file mode 100644
index 20f489c4e6157..0000000000000
--- a/compiler/testData/diagnostics/tests/multimodule/redundantElseInWhen.fir.kt
+++ /dev/null
@@ -1,49 +0,0 @@
-// RUN_PIPELINE_TILL: BACKEND
-// MODULE: m1
-// FILE: a.kt
-
-package test
-
-enum class E {
-    FIRST
-}
-
-sealed class S
-
-class Derived : S()
-
-// MODULE: m2(m1)
-// FILE: b.kt
-
-package other
-
-import test.*
-
-fun foo(e: E) = when (e) {
-    E.FIRST -> 42
-    <!REDUNDANT_ELSE_IN_WHEN!>else<!> -> -42
-}
-
-fun bar(s: S?) = when (s) {
-    is Derived -> "Derived"
-    null -> ""
-    <!REDUNDANT_ELSE_IN_WHEN!>else<!> -> TODO("What?!?!")
-}
-
-fun baz(b: Boolean?) = when (b) {
-    true -> 1
-    false -> 0
-    null -> -1
-    // Still warning
-    <!REDUNDANT_ELSE_IN_WHEN!>else<!> -> TODO()
-}
-
-fun baz(b: Boolean) = when (b) {
-    true -> 1
-    false -> 0
-    // Still warning
-    <!REDUNDANT_ELSE_IN_WHEN!>else<!> -> TODO()
-}
-
-/* GENERATED_FIR_TAGS: classDeclaration, enumDeclaration, enumEntry, equalityExpression, functionDeclaration,
-integerLiteral, isExpression, nullableType, sealed, smartcast, stringLiteral, whenExpression, whenWithSubject */
diff --git a/compiler/testData/diagnostics/tests/multimodule/redundantElseInWhen.kt b/compiler/testData/diagnostics/tests/multimodule/redundantElseInWhen.kt
index 4be944ba30960..313b131f27b1e 100644
--- a/compiler/testData/diagnostics/tests/multimodule/redundantElseInWhen.kt
+++ b/compiler/testData/diagnostics/tests/multimodule/redundantElseInWhen.kt
@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // RUN_PIPELINE_TILL: BACKEND
 // MODULE: m1
 // FILE: a.kt