diff --git a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/SupertypeUtils.kt b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/SupertypeUtils.kt
index 0f49105932c..a047ab96c0c 100644
--- a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/SupertypeUtils.kt
+++ b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/SupertypeUtils.kt
@@ -64,7 +64,7 @@ fun collectSymbolsForType(type: ConeKotlinType, useSiteSession: FirSession): Lis
 }
 
 fun lookupSuperTypes(
-    symbols: List<FirClassifierSymbol<*>>,
+    symbols: List<FirClassSymbol<*>>,
     lookupInterfaces: Boolean,
     deep: Boolean,
     useSiteSession: FirSession,
@@ -161,7 +161,7 @@ fun FirClass.isThereLoopInSupertypes(session: FirSession): Boolean {
 }
 
 fun lookupSuperTypes(
-    symbol: FirClassifierSymbol<*>,
+    symbol: FirClassLikeSymbol<*>,
     lookupInterfaces: Boolean,
     deep: Boolean,
     useSiteSession: FirSession
@@ -231,7 +231,7 @@ private fun ConeClassLikeType.computePartialExpansion(
     supertypeSupplier: SupertypeSupplier
 ): ConeClassLikeType = fullyExpandedType(useSiteSession) { supertypeSupplier.expansionForTypeAlias(it, useSiteSession) }
 
-private fun FirClassifierSymbol<*>.collectSuperTypes(
+private fun FirClassLikeSymbol<*>.collectSuperTypes(
     list: MutableList<ConeClassLikeType>,
     visitedSymbols: MutableSet<FirClassifierSymbol<*>>,
     deep: Boolean,
@@ -287,7 +287,6 @@ private fun FirClassifierSymbol<*>.collectSuperTypes(
             expansion.lookupTag.toSymbol(useSiteSession)
                 ?.collectSuperTypes(list, visitedSymbols, deep, lookupInterfaces, substituteSuperTypes, useSiteSession, supertypeSupplier)
         }
-        else -> error("?!id:1")
     }
 }
 
diff --git a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/calls/Synthetics.kt b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/calls/Synthetics.kt
index 0e9ec4c449d..51ca5dad8d0 100644
--- a/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/calls/Synthetics.kt
+++ b/compiler/fir/providers/src/org/jetbrains/kotlin/fir/resolve/calls/Synthetics.kt
@@ -15,8 +15,10 @@ import org.jetbrains.kotlin.fir.resolve.toSymbol
 import org.jetbrains.kotlin.fir.resolve.transformers.ReturnTypeCalculator
 import org.jetbrains.kotlin.fir.scopes.*
 import org.jetbrains.kotlin.fir.symbols.SyntheticSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirClassLikeSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirNamedFunctionSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirSyntheticPropertySymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirTypeParameterSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirVariableSymbol
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.name.CallableId
@@ -277,7 +279,7 @@ class FirSyntheticPropertiesScope private constructor(
      */
     private fun isJavaTypeOnThePath(baseType: ConeSimpleKotlinType?): Boolean {
         val lookupTagToStop = (baseType as? ConeLookupTagBasedType)?.lookupTag ?: return false
-        val dispatchReceiverClass = (dispatchReceiverType as? ConeLookupTagBasedType)?.lookupTag?.toSymbol(session) ?: return false
+        val dispatchReceiverClassSymbol = (dispatchReceiverType as? ConeLookupTagBasedType)?.lookupTag?.toSymbol(session) ?: return false
 
         val typeContext = session.typeContext
         fun checkType(type: ConeClassLikeType): Boolean {
@@ -294,10 +296,17 @@ class FirSyntheticPropertiesScope private constructor(
             return true
         }
 
-        val superTypes = lookupSuperTypes(dispatchReceiverClass, lookupInterfaces = true, deep = true, session)
-        for (superType in superTypes) {
-            if (checkType(superType)) return true
+        when (dispatchReceiverClassSymbol) {
+            is FirClassLikeSymbol -> {
+                val superTypes = lookupSuperTypes(dispatchReceiverClassSymbol, lookupInterfaces = true, deep = true, session)
+                for (superType in superTypes) {
+                    if (checkType(superType)) return true
+                }
+                return false
+            }
+            is FirTypeParameterSymbol -> {
+                error("Type parameter symbol ${dispatchReceiverClassSymbol.name} is not expected here")
+            }
         }
-        return false
     }
 }