diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/FirDataFlowAnalyzer.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/FirDataFlowAnalyzer.kt
index 36f0592df6a..4272d28e9ec 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/FirDataFlowAnalyzer.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/FirDataFlowAnalyzer.kt
@@ -16,24 +16,27 @@ import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.references.FirControlFlowGraphReference
 import org.jetbrains.kotlin.fir.references.FirResolvedNamedReference
-import org.jetbrains.kotlin.fir.resolve.*
+import org.jetbrains.kotlin.fir.resolve.PersistentImplicitReceiverStack
+import org.jetbrains.kotlin.fir.resolve.ResolutionMode
 import org.jetbrains.kotlin.fir.resolve.dfa.cfg.*
 import org.jetbrains.kotlin.fir.resolve.dfa.contracts.buildContractFir
 import org.jetbrains.kotlin.fir.resolve.dfa.contracts.createArgumentsMapping
+import org.jetbrains.kotlin.fir.resolve.fullyExpandedType
 import org.jetbrains.kotlin.fir.resolve.inference.inferenceComponents
 import org.jetbrains.kotlin.fir.resolve.substitution.ConeSubstitutor
 import org.jetbrains.kotlin.fir.resolve.substitution.ConeSubstitutorByMap
+import org.jetbrains.kotlin.fir.resolve.toSymbol
 import org.jetbrains.kotlin.fir.resolve.transformers.body.resolve.FirAbstractBodyResolveTransformer
 import org.jetbrains.kotlin.fir.resolve.transformers.body.resolve.resultType
 import org.jetbrains.kotlin.fir.symbols.AbstractFirBasedSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirTypeParameterSymbol
-import org.jetbrains.kotlin.name.CallableId
-import org.jetbrains.kotlin.name.StandardClassIds
 import org.jetbrains.kotlin.fir.symbols.impl.FirVariableSymbol
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.fir.visitors.transformSingle
+import org.jetbrains.kotlin.name.CallableId
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.name.StandardClassIds
 import org.jetbrains.kotlin.types.ConstantValueKind
 import org.jetbrains.kotlin.utils.addIfNotNull
 
@@ -441,7 +444,7 @@ abstract class FirDataFlowAnalyzer<FLOW : Flow>(
         val operandVariable = variableStorage.getOrCreateVariable(node.previousFlow, operand)
         // expression == const -> expression != null
         flow.addImplication((expressionVariable eq isEq) implies (operandVariable notEq null))
-        if (operandVariable is RealVariable) {
+        if (operandVariable.isReal()) {
             flow.addImplication((expressionVariable eq isEq) implies (operandVariable typeEq any))
         }
 
@@ -820,7 +823,7 @@ abstract class FirDataFlowAnalyzer<FLOW : Flow>(
                 ?: return@let
 
             val variable = variableStorage.getOrCreateVariable(flow, receiver)
-            if (variable is RealVariable) {
+            if (variable.isReal()) {
                 if (shouldFork) {
                     flow = logicSystem.forkFlow(flow)
                 }
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/VariableStorage.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/VariableStorage.kt
index 1d33225ba4a..4e8854bca5e 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/VariableStorage.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/VariableStorage.kt
@@ -138,7 +138,7 @@ class VariableStorage(private val session: FirSession) {
     }
 
     fun removeSyntheticVariable(variable: DataFlowVariable) {
-        if (variable !is SyntheticVariable) return
+        if (!variable.isSynthetic()) return
         syntheticVariables.remove(variable.fir)
     }