diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirInlineClassDeclarationChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirInlineClassDeclarationChecker.kt
index da45c73392b..f6266b6af59 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirInlineClassDeclarationChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirInlineClassDeclarationChecker.kt
@@ -218,7 +218,8 @@ object FirInlineClassDeclarationChecker : FirRegularClassChecker() {
     private fun FirRegularClass.isSubtypeOfCloneable(session: FirSession): Boolean {
         if (classId.isCloneableId()) return true
 
-        return lookupSuperTypes(this, lookupInterfaces = true, deep = true, session).any { superType ->
+        return lookupSuperTypes(this, lookupInterfaces = true, deep = true, session, substituteTypes = false).any { superType ->
+            // Note: We check just classId here, so type substitution isn't needed   ^ (we aren't interested in type arguments)
             (superType as? ConeClassLikeType)?.fullyExpandedType(session)?.lookupTag?.classId?.isCloneableId() == true
         }
     }
diff --git a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/FirVisibilityChecker.kt b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/FirVisibilityChecker.kt
index a6d79f134cf..3a81390cf5e 100644
--- a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/FirVisibilityChecker.kt
+++ b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/FirVisibilityChecker.kt
@@ -237,7 +237,8 @@ abstract class FirVisibilityChecker : FirSessionComponent {
     private fun FirClass.isSubClass(ownerLookupTag: ConeClassLikeLookupTag, session: FirSession): Boolean {
         if (classId.isSame(ownerLookupTag.classId)) return true
 
-        return lookupSuperTypes(this, lookupInterfaces = true, deep = true, session).any { superType ->
+        return lookupSuperTypes(this, lookupInterfaces = true, deep = true, session, substituteTypes = false).any { superType ->
+            // Note: We check just classId here, so type substitution isn't needed   ^ (we aren't interested in type arguments)
             (superType as? ConeClassLikeType)?.fullyExpandedType(session)?.lookupTag?.classId?.isSame(ownerLookupTag.classId) == true
         }
     }
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/SamResolution.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/SamResolution.kt
index ba453c862b2..9242d12263f 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/SamResolution.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/SamResolution.kt
@@ -251,7 +251,8 @@ private fun FirRegularClass.getSingleAbstractMethodOrNull(
 
 private fun FirRegularClass.computeSamCandidateNames(session: FirSession): Set<Name> {
     val classes =
-        lookupSuperTypes(this, lookupInterfaces = true, deep = true, useSiteSession = session)
+        // Note: we search only for names in this function, so substitution is not needed      V
+        lookupSuperTypes(this, lookupInterfaces = true, deep = true, useSiteSession = session, substituteTypes = false)
             .mapNotNullTo(mutableListOf(this)) {
                 (session.symbolProvider.getSymbolByLookupTag(it.lookupTag) as? FirRegularClassSymbol)?.fir
             }