diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/coroutines/SpilledVariableFieldTypesAnalysis.kt b/compiler/backend/src/org/jetbrains/kotlin/codegen/coroutines/SpilledVariableFieldTypesAnalysis.kt
index fcb282ab2a3..d09d7ea2295 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/coroutines/SpilledVariableFieldTypesAnalysis.kt
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/coroutines/SpilledVariableFieldTypesAnalysis.kt
@@ -161,7 +161,7 @@ private fun Type.isIntLike(): Boolean = when (sort) {
 }
 
 // Represents [ACONST_NULL, CHECKCAST Type] sequence result.
-internal class TypedNullValue(type: Type) : BasicValue(type)
+internal class TypedNullValue(type: Type) : StrictBasicValue(type)
 
 // Preserves nulls through CHECKCASTS.
 private class NullCheckcastAwareOptimizationBasicInterpreter : OptimizationBasicInterpreter() {
@@ -171,4 +171,12 @@ private class NullCheckcastAwareOptimizationBasicInterpreter : OptimizationBasic
         }
         return super.unaryOperation(insn, value)
     }
-}
\ No newline at end of file
+
+    override fun merge(v: BasicValue, w: BasicValue): BasicValue =
+        when {
+            v is TypedNullValue && w is TypedNullValue -> if (v.type == w.type) v else StrictBasicValue.NULL_VALUE
+            v is TypedNullValue -> super.merge(StrictBasicValue.NULL_VALUE, w)
+            w is TypedNullValue -> super.merge(v, StrictBasicValue.NULL_VALUE)
+            else -> super.merge(v, w)
+        }
+}
diff --git a/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java b/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java
index ca6d8e329da..fc484910e84 100644
--- a/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java
+++ b/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java
@@ -10209,6 +10209,18 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/coroutines/kt51718.kt");
         }
 
+        @Test
+        @TestMetadata("kt52311_nullOnLeft.kt")
+        public void testKt52311_nullOnLeft() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnLeft.kt");
+        }
+
+        @Test
+        @TestMetadata("kt52311_nullOnRight.kt")
+        public void testKt52311_nullOnRight() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnRight.kt");
+        }
+
         @Test
         @TestMetadata("lastExpressionIsLoop.kt")
         public void testLastExpressionIsLoop() throws Exception {
diff --git a/compiler/testData/codegen/box/coroutines/kt52311_nullOnLeft.kt b/compiler/testData/codegen/box/coroutines/kt52311_nullOnLeft.kt
new file mode 100644
index 00000000000..160a13a74c0
--- /dev/null
+++ b/compiler/testData/codegen/box/coroutines/kt52311_nullOnLeft.kt
@@ -0,0 +1,29 @@
+// WITH_STDLIB
+// WITH_COROUTINES
+import helpers.*
+import kotlin.coroutines.*
+import kotlin.coroutines.intrinsics.*
+
+fun someCondition() = true
+
+suspend fun suspendHere() = suspendCoroutineUninterceptedOrReturn {
+    it.resume(Unit)
+    COROUTINE_SUSPENDED
+}
+
+fun expectString(x: String?) = x!!
+
+suspend fun foo(): String {
+    var x: String? = null
+    if (someCondition()) {
+        x = "OK"
+    }
+    suspendHere()
+    return expectString(x)
+}
+
+fun box(): String {
+    var result = "fail"
+    suspend { result = foo() }.startCoroutine(EmptyContinuation)
+    return result
+}
\ No newline at end of file
diff --git a/compiler/testData/codegen/box/coroutines/kt52311_nullOnRight.kt b/compiler/testData/codegen/box/coroutines/kt52311_nullOnRight.kt
new file mode 100644
index 00000000000..8321868f6be
--- /dev/null
+++ b/compiler/testData/codegen/box/coroutines/kt52311_nullOnRight.kt
@@ -0,0 +1,29 @@
+// WITH_STDLIB
+// WITH_COROUTINES
+import helpers.*
+import kotlin.coroutines.*
+import kotlin.coroutines.intrinsics.*
+
+fun someCondition() = false
+
+suspend fun suspendHere() = suspendCoroutineUninterceptedOrReturn {
+    it.resume(Unit)
+    COROUTINE_SUSPENDED
+}
+
+fun expectString(x: String?) = x!!
+
+suspend fun foo(): String {
+    var x: String? = "OK"
+    if (someCondition()) {
+        x = null as String?
+    }
+    suspendHere()
+    return expectString(x)
+}
+
+fun box(): String {
+    var result = "fail"
+    suspend { result = foo() }.startCoroutine(EmptyContinuation)
+    return result
+}
diff --git a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java
index 5442e1c0659..da21eed07c0 100644
--- a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java
+++ b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java
@@ -10089,6 +10089,18 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/coroutines/kt51718.kt");
         }
 
+        @Test
+        @TestMetadata("kt52311_nullOnLeft.kt")
+        public void testKt52311_nullOnLeft() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnLeft.kt");
+        }
+
+        @Test
+        @TestMetadata("kt52311_nullOnRight.kt")
+        public void testKt52311_nullOnRight() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnRight.kt");
+        }
+
         @Test
         @TestMetadata("lastExpressionIsLoop.kt")
         public void testLastExpressionIsLoop() throws Exception {
diff --git a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java
index 5ff0ca6abe0..ed0985ff3bf 100644
--- a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java
+++ b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java
@@ -10209,6 +10209,18 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/coroutines/kt51718.kt");
         }
 
+        @Test
+        @TestMetadata("kt52311_nullOnLeft.kt")
+        public void testKt52311_nullOnLeft() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnLeft.kt");
+        }
+
+        @Test
+        @TestMetadata("kt52311_nullOnRight.kt")
+        public void testKt52311_nullOnRight() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnRight.kt");
+        }
+
         @Test
         @TestMetadata("lastExpressionIsLoop.kt")
         public void testLastExpressionIsLoop() throws Exception {
diff --git a/compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java b/compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java
index 39a65f3e489..3248bc9567f 100644
--- a/compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java
+++ b/compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java
@@ -7944,6 +7944,16 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/coroutines/kt51718.kt");
         }
 
+        @TestMetadata("kt52311_nullOnLeft.kt")
+        public void testKt52311_nullOnLeft() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnLeft.kt");
+        }
+
+        @TestMetadata("kt52311_nullOnRight.kt")
+        public void testKt52311_nullOnRight() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnRight.kt");
+        }
+
         @TestMetadata("lastExpressionIsLoop.kt")
         public void testLastExpressionIsLoop() throws Exception {
             runTest("compiler/testData/codegen/box/coroutines/lastExpressionIsLoop.kt");
diff --git a/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/JsCodegenBoxTestGenerated.java b/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/JsCodegenBoxTestGenerated.java
index 8643afabeec..60900f644af 100644
--- a/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/JsCodegenBoxTestGenerated.java
+++ b/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/JsCodegenBoxTestGenerated.java
@@ -7181,6 +7181,18 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/coroutines/kt51718.kt");
         }
 
+        @Test
+        @TestMetadata("kt52311_nullOnLeft.kt")
+        public void testKt52311_nullOnLeft() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnLeft.kt");
+        }
+
+        @Test
+        @TestMetadata("kt52311_nullOnRight.kt")
+        public void testKt52311_nullOnRight() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnRight.kt");
+        }
+
         @Test
         @TestMetadata("lastExpressionIsLoop.kt")
         public void testLastExpressionIsLoop() throws Exception {
diff --git a/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsCodegenBoxTestGenerated.java b/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsCodegenBoxTestGenerated.java
index 91bfd3121a5..494aae48c54 100644
--- a/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsCodegenBoxTestGenerated.java
+++ b/js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsCodegenBoxTestGenerated.java
@@ -7223,6 +7223,18 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/coroutines/kt51718.kt");
         }
 
+        @Test
+        @TestMetadata("kt52311_nullOnLeft.kt")
+        public void testKt52311_nullOnLeft() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnLeft.kt");
+        }
+
+        @Test
+        @TestMetadata("kt52311_nullOnRight.kt")
+        public void testKt52311_nullOnRight() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnRight.kt");
+        }
+
         @Test
         @TestMetadata("lastExpressionIsLoop.kt")
         public void testLastExpressionIsLoop() throws Exception {
diff --git a/js/js.tests/tests-gen/org/jetbrains/kotlin/js/testOld/wasm/semantics/IrCodegenBoxWasmTestGenerated.java b/js/js.tests/tests-gen/org/jetbrains/kotlin/js/testOld/wasm/semantics/IrCodegenBoxWasmTestGenerated.java
index ca50f66fe6c..b2112ec07bb 100644
--- a/js/js.tests/tests-gen/org/jetbrains/kotlin/js/testOld/wasm/semantics/IrCodegenBoxWasmTestGenerated.java
+++ b/js/js.tests/tests-gen/org/jetbrains/kotlin/js/testOld/wasm/semantics/IrCodegenBoxWasmTestGenerated.java
@@ -6354,6 +6354,16 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/coroutines/kt51718.kt");
         }
 
+        @TestMetadata("kt52311_nullOnLeft.kt")
+        public void testKt52311_nullOnLeft() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnLeft.kt");
+        }
+
+        @TestMetadata("kt52311_nullOnRight.kt")
+        public void testKt52311_nullOnRight() throws Exception {
+            runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnRight.kt");
+        }
+
         @TestMetadata("lastExpressionIsLoop.kt")
         public void testLastExpressionIsLoop() throws Exception {
             runTest("compiler/testData/codegen/box/coroutines/lastExpressionIsLoop.kt");
diff --git a/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/blackboxtest/NativeCodegenBoxTestGenerated.java b/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/blackboxtest/NativeCodegenBoxTestGenerated.java
index b519076ecea..0c1f85f2542 100644
--- a/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/blackboxtest/NativeCodegenBoxTestGenerated.java
+++ b/native/native.tests/tests-gen/org/jetbrains/kotlin/konan/blackboxtest/NativeCodegenBoxTestGenerated.java
@@ -8065,6 +8065,18 @@ public class NativeCodegenBoxTestGenerated extends AbstractNativeCodegenBoxTest
                 runTest("compiler/testData/codegen/box/coroutines/kt51718.kt");
             }
 
+            @Test
+            @TestMetadata("kt52311_nullOnLeft.kt")
+            public void testKt52311_nullOnLeft() throws Exception {
+                runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnLeft.kt");
+            }
+
+            @Test
+            @TestMetadata("kt52311_nullOnRight.kt")
+            public void testKt52311_nullOnRight() throws Exception {
+                runTest("compiler/testData/codegen/box/coroutines/kt52311_nullOnRight.kt");
+            }
+
             @Test
             @TestMetadata("lastExpressionIsLoop.kt")
             public void testLastExpressionIsLoop() throws Exception {