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 89e741b9de2..349cbe78531 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
@@ -268,8 +268,15 @@ abstract class FirDataFlowAnalyzer<FLOW : Flow>(
                 expressionVariable,
                 shouldRemoveOriginalStatements = operandVariable.isSynthetic()
             ) {
-                if (shouldInvert) (it.condition.invert()) implies (it.effect)
-                else it
+                when (it.condition.operation) {
+                    Operation.EqNull, Operation.NotEqNull -> {
+                        (expressionVariable eq isEq) implies (it.effect)
+                    }
+                    Operation.EqTrue, Operation.EqFalse -> {
+                        if (shouldInvert) (it.condition.invert()) implies (it.effect)
+                        else it
+                    }
+                }
             }
         }
     }
diff --git a/compiler/fir/resolve/testData/resolve/expresssions/genericDescriptor.kt b/compiler/fir/resolve/testData/resolve/expresssions/genericDescriptor.kt
index 764d16a0cd9..1c089007e2b 100644
--- a/compiler/fir/resolve/testData/resolve/expresssions/genericDescriptor.kt
+++ b/compiler/fir/resolve/testData/resolve/expresssions/genericDescriptor.kt
@@ -32,7 +32,7 @@ fun <D : Descriptor> test(call: Call<D>, resolvedCall: ResolvedCall<D>) {
 
     val resolvedDescriptor = resolvedCall.candidateDescriptor
     if (resolvedDescriptor?.correct() != true) return
-    resolvedDescriptor.<!INAPPLICABLE_CANDIDATE!>foo<!>()
+    resolvedDescriptor.foo()
 }
 
 fun otherTest(call: Call<*>, resolvedCall: ResolvedCall<*>) {
diff --git a/compiler/fir/resolve/testData/resolve/expresssions/genericDescriptor.txt b/compiler/fir/resolve/testData/resolve/expresssions/genericDescriptor.txt
index b167bec8965..c7646d1e673 100644
--- a/compiler/fir/resolve/testData/resolve/expresssions/genericDescriptor.txt
+++ b/compiler/fir/resolve/testData/resolve/expresssions/genericDescriptor.txt
@@ -21,7 +21,7 @@ FILE: test.kt
             }
         }
 
-        R|<local>/resolvedDescriptor|.<Inapplicable(WRONG_RECEIVER): [/foo]>#()
+        R|<local>/resolvedDescriptor|.R|/foo|()
     }
     public final fun otherTest(call: R|Call<*>|, resolvedCall: R|ResolvedCall<*>|): R|kotlin/Unit| {
         R|<local>/call|.R|FakeOverride</Call.resultingDescriptor: R|Descriptor|>|.R|/name|
diff --git a/compiler/fir/resolve/testData/resolve/stdlib/problems/complexSmartCasts.kt b/compiler/fir/resolve/testData/resolve/stdlib/problems/complexSmartCasts.kt
index 165543e7a17..769a21a8b29 100644
--- a/compiler/fir/resolve/testData/resolve/stdlib/problems/complexSmartCasts.kt
+++ b/compiler/fir/resolve/testData/resolve/stdlib/problems/complexSmartCasts.kt
@@ -12,10 +12,36 @@ fun foo(a: Any?) {
 
 fun bar(s: String?) {
     if (s?.isNotEmpty() == true) {
+        s.length
+    } else {
         s.<!INAPPLICABLE_CANDIDATE!>length<!>
     }
 }
 
+fun bar_2(s: String?) {
+    if (s?.isNotEmpty() == false) {
+        s.length
+    } else {
+        s.<!INAPPLICABLE_CANDIDATE!>length<!>
+    }
+}
+
+fun bar_3(s: String?) {
+    if (s?.isNotEmpty() != true) {
+        s.<!INAPPLICABLE_CANDIDATE!>length<!>
+    } else {
+        s.length
+    }
+}
+
+fun bar_4(s: String?) {
+    if (s?.isNotEmpty() != false) {
+        s.<!INAPPLICABLE_CANDIDATE!>length<!>
+    } else {
+        s.length
+    }
+}
+
 fun baz(s: String?) {
     when {
         !s.isNullOrEmpty() -> s.<!INAPPLICABLE_CANDIDATE!>length<!>
diff --git a/compiler/fir/resolve/testData/resolve/stdlib/problems/complexSmartCasts.txt b/compiler/fir/resolve/testData/resolve/stdlib/problems/complexSmartCasts.txt
index 23843c1fb42..993376163fd 100644
--- a/compiler/fir/resolve/testData/resolve/stdlib/problems/complexSmartCasts.txt
+++ b/compiler/fir/resolve/testData/resolve/stdlib/problems/complexSmartCasts.txt
@@ -25,10 +25,46 @@ FILE: complexSmartCasts.kt
     public final fun bar(s: R|kotlin/String?|): R|kotlin/Unit| {
         when () {
             ==(R|<local>/s|?.R|kotlin/text/isNotEmpty|(), Boolean(true)) ->  {
+                R|<local>/s|.R|kotlin/String.length|
+            }
+            else ->  {
                 R|<local>/s|.<Inapplicable(WRONG_RECEIVER): [kotlin/String.length]>#
             }
         }
 
+    }
+    public final fun bar_2(s: R|kotlin/String?|): R|kotlin/Unit| {
+        when () {
+            ==(R|<local>/s|?.R|kotlin/text/isNotEmpty|(), Boolean(false)) ->  {
+                R|<local>/s|.R|kotlin/String.length|
+            }
+            else ->  {
+                R|<local>/s|.<Inapplicable(WRONG_RECEIVER): [kotlin/String.length]>#
+            }
+        }
+
+    }
+    public final fun bar_3(s: R|kotlin/String?|): R|kotlin/Unit| {
+        when () {
+            !=(R|<local>/s|?.R|kotlin/text/isNotEmpty|(), Boolean(true)) ->  {
+                R|<local>/s|.<Inapplicable(WRONG_RECEIVER): [kotlin/String.length]>#
+            }
+            else ->  {
+                R|<local>/s|.R|kotlin/String.length|
+            }
+        }
+
+    }
+    public final fun bar_4(s: R|kotlin/String?|): R|kotlin/Unit| {
+        when () {
+            !=(R|<local>/s|?.R|kotlin/text/isNotEmpty|(), Boolean(false)) ->  {
+                R|<local>/s|.<Inapplicable(WRONG_RECEIVER): [kotlin/String.length]>#
+            }
+            else ->  {
+                R|<local>/s|.R|kotlin/String.length|
+            }
+        }
+
     }
     public final fun baz(s: R|kotlin/String?|): R|kotlin/Unit| {
         when () {