diff --git a/compiler/fir/semantics/src/org/jetbrains/kotlin/fir/resolve/dfa/VariableStorageImpl.kt b/compiler/fir/semantics/src/org/jetbrains/kotlin/fir/resolve/dfa/VariableStorageImpl.kt
index 497a02d0a0a..8cd15f7bd61 100644
--- a/compiler/fir/semantics/src/org/jetbrains/kotlin/fir/resolve/dfa/VariableStorageImpl.kt
+++ b/compiler/fir/semantics/src/org/jetbrains/kotlin/fir/resolve/dfa/VariableStorageImpl.kt
@@ -9,14 +9,9 @@ import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.fir.FirElement
 import org.jetbrains.kotlin.fir.FirSession
-import org.jetbrains.kotlin.fir.declarations.FirAnonymousObject
-import org.jetbrains.kotlin.fir.declarations.FirProperty
-import org.jetbrains.kotlin.fir.declarations.FirRegularClass
+import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertyAccessor
-import org.jetbrains.kotlin.fir.declarations.utils.isExpect
-import org.jetbrains.kotlin.fir.declarations.utils.isFinal
-import org.jetbrains.kotlin.fir.declarations.utils.modality
-import org.jetbrains.kotlin.fir.declarations.utils.visibility
+import org.jetbrains.kotlin.fir.declarations.utils.*
 import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.moduleData
 import org.jetbrains.kotlin.fir.originalOrSelf
@@ -170,7 +165,25 @@ class VariableStorageImpl(private val session: FirSession) : VariableStorage() {
         if (this !is FirVariableSymbol<*>) return null
         if (this is FirFieldSymbol && !this.isFinal) return PropertyStability.MUTABLE_PROPERTY
 
-        val property = this.fir as? FirProperty ?: return PropertyStability.STABLE_VALUE
+        val property = when (val variable = this.fir) { // intentionally exhaustive 'when'
+            is FirEnumEntry, is FirErrorProperty, is FirValueParameter -> return PropertyStability.STABLE_VALUE
+
+            // NB: FirJavaField is expected here. FirFieldImpl should've been handled by FirBackingFieldSymbol check above
+            is FirField -> {
+                if (variable.isJava)
+                    return variable.determineStabilityByModule()
+                else
+                    errorWithAttachment("Expected to handle non-Java FirFields via symbol-based checks") {
+                        withFirEntry("fir", variable)
+                    }
+            }
+
+            is FirBackingField -> errorWithAttachment("Expected to handle Backing Field entirely via symbol-based checks") {
+                withFirEntry("fir", variable)
+            }
+
+            is FirProperty -> variable
+        }
 
         return when {
             property.delegate != null -> PropertyStability.DELEGATED_PROPERTY
@@ -192,16 +205,19 @@ class VariableStorageImpl(private val session: FirSession) : VariableStorage() {
                     }
                 }
             }
-            else -> {
-                val propertyModuleData = property.originalOrSelf().moduleData
-                val currentModuleData = session.moduleData
-                when (propertyModuleData) {
-                    currentModuleData,
-                    in currentModuleData.friendDependencies,
-                    in currentModuleData.dependsOnDependencies -> PropertyStability.STABLE_VALUE
-                    else -> PropertyStability.ALIEN_PUBLIC_PROPERTY
-                }
-            }
+            else -> property.determineStabilityByModule()
+        }
+    }
+
+    private fun FirVariable.determineStabilityByModule(): PropertyStability {
+        val propertyModuleData = originalOrSelf().moduleData
+        val currentModuleData = session.moduleData
+        return when (propertyModuleData) {
+            currentModuleData,
+            in currentModuleData.friendDependencies,
+            in currentModuleData.dependsOnDependencies,
+            -> PropertyStability.STABLE_VALUE
+            else -> PropertyStability.ALIEN_PUBLIC_PROPERTY
         }
     }
 }
diff --git a/compiler/testData/diagnostics/tests/smartCasts/variables/staticJavaFieldFromOtherModule.kt b/compiler/testData/diagnostics/tests/smartCasts/variables/staticJavaFieldFromOtherModule.kt
index 4764ba7c8a9..82ab73fd28b 100644
--- a/compiler/testData/diagnostics/tests/smartCasts/variables/staticJavaFieldFromOtherModule.kt
+++ b/compiler/testData/diagnostics/tests/smartCasts/variables/staticJavaFieldFromOtherModule.kt
@@ -11,8 +11,8 @@ public class J {
 // MODULE: app(lib)
 fun isCast() {
     if (J.staticFinalJava is String) {
-        J.staticFinalJava.length
-        (J.staticFinalJava <!USELESS_CAST!>as String<!>).length
+        <!SMARTCAST_IMPOSSIBLE!>J.staticFinalJava<!>.length
+        (J.staticFinalJava as String).length
     }
 
     if (J.staticNonFinalJava is String) {
@@ -23,7 +23,7 @@ fun isCast() {
 
 fun asCast() {
     J.staticFinalJava as String
-    J.staticFinalJava.length
+    <!SMARTCAST_IMPOSSIBLE!>J.staticFinalJava<!>.length
 
     J.staticNonFinalJava as String
     <!SMARTCAST_IMPOSSIBLE!>J.staticNonFinalJava<!>.length