diff --git a/compiler/fir/analysis-tests/legacy-fir-tests/tests-gen/org/jetbrains/kotlin/fir/LazyBodyIsNotTouchedTilContractsPhaseTestGenerated.java b/compiler/fir/analysis-tests/legacy-fir-tests/tests-gen/org/jetbrains/kotlin/fir/LazyBodyIsNotTouchedTilContractsPhaseTestGenerated.java
index ae7e3528124..418a7c3a1bf 100644
--- a/compiler/fir/analysis-tests/legacy-fir-tests/tests-gen/org/jetbrains/kotlin/fir/LazyBodyIsNotTouchedTilContractsPhaseTestGenerated.java
+++ b/compiler/fir/analysis-tests/legacy-fir-tests/tests-gen/org/jetbrains/kotlin/fir/LazyBodyIsNotTouchedTilContractsPhaseTestGenerated.java
@@ -1274,6 +1274,11 @@ public class LazyBodyIsNotTouchedTilContractsPhaseTestGenerated extends Abstract
             public void testMissingSealedInheritor() throws Exception {
                 runTest("compiler/fir/analysis-tests/testData/resolve/exhaustiveness/negative/missingSealedInheritor.kt");
             }
+
+            @TestMetadata("nonExhaustiveWhenWithoutCoercionToUnit.kt")
+            public void testNonExhaustiveWhenWithoutCoercionToUnit() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolve/exhaustiveness/negative/nonExhaustiveWhenWithoutCoercionToUnit.kt");
+            }
         }
 
         @TestMetadata("compiler/fir/analysis-tests/testData/resolve/exhaustiveness/positive")
@@ -1327,6 +1332,11 @@ public class LazyBodyIsNotTouchedTilContractsPhaseTestGenerated extends Abstract
             public void testExhaustiveness_sealedSubClass() throws Exception {
                 runTest("compiler/fir/analysis-tests/testData/resolve/exhaustiveness/positive/exhaustiveness_sealedSubClass.kt");
             }
+
+            @TestMetadata("nonExhaustiveWhenWithCoercionToUnit.kt")
+            public void testNonExhaustiveWhenWithCoercionToUnit() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolve/exhaustiveness/positive/nonExhaustiveWhenWithCoercionToUnit.kt");
+            }
         }
     }
 
diff --git a/compiler/fir/analysis-tests/testData/resolve/exhaustiveness/negative/nonExhaustiveWhenWithoutCoercionToUnit.fir.txt b/compiler/fir/analysis-tests/testData/resolve/exhaustiveness/negative/nonExhaustiveWhenWithoutCoercionToUnit.fir.txt
new file mode 100644
index 00000000000..3dbef094d39
--- /dev/null
+++ b/compiler/fir/analysis-tests/testData/resolve/exhaustiveness/negative/nonExhaustiveWhenWithoutCoercionToUnit.fir.txt
@@ -0,0 +1,15 @@
+FILE: nonExhaustiveWhenWithoutCoercionToUnit.kt
+    public final fun <T> run(block: R|() -> T|): R|T| {
+        ^run R|<local>/block|.R|SubstitutionOverride<kotlin/Function0.invoke: R|T|>|()
+    }
+    public final fun test(a: R|kotlin/Any|): R|kotlin/Unit| {
+        R|/run|<R|kotlin/Unit|>(<L> = run@fun <anonymous>(): R|kotlin/Unit| {
+            when (R|<local>/a|) {
+                ($subj$ is R|kotlin/String|) ->  {
+                    Int(1)
+                }
+            }
+
+        }
+        )
+    }
diff --git a/compiler/fir/analysis-tests/testData/resolve/exhaustiveness/negative/nonExhaustiveWhenWithoutCoercionToUnit.kt b/compiler/fir/analysis-tests/testData/resolve/exhaustiveness/negative/nonExhaustiveWhenWithoutCoercionToUnit.kt
new file mode 100644
index 00000000000..35d276b48ea
--- /dev/null
+++ b/compiler/fir/analysis-tests/testData/resolve/exhaustiveness/negative/nonExhaustiveWhenWithoutCoercionToUnit.kt
@@ -0,0 +1,10 @@
+fun <T> run(block: () -> T): T = block()
+
+fun test(a: Any) {
+    run {
+        // Should be an error, see KT-44810
+        when (a) {
+            is String -> 1
+        }
+    }
+}
diff --git a/compiler/fir/analysis-tests/testData/resolve/exhaustiveness/positive/nonExhaustiveWhenWithCoercionToUnit.fir.txt b/compiler/fir/analysis-tests/testData/resolve/exhaustiveness/positive/nonExhaustiveWhenWithCoercionToUnit.fir.txt
new file mode 100644
index 00000000000..3c426b78f6e
--- /dev/null
+++ b/compiler/fir/analysis-tests/testData/resolve/exhaustiveness/positive/nonExhaustiveWhenWithCoercionToUnit.fir.txt
@@ -0,0 +1,21 @@
+FILE: nonExhaustiveWhenWithCoercionToUnit.kt
+    public final fun <T> run(block: R|() -> T|): R|T| {
+        ^run R|<local>/block|.R|SubstitutionOverride<kotlin/Function0.invoke: R|T|>|()
+    }
+    public final fun test(a: R|kotlin/Any|, b: R|kotlin/Boolean|): R|kotlin/Unit| {
+        R|/run|<R|kotlin/Unit|>(<L> = run@fun <anonymous>(): R|kotlin/Unit| {
+            when () {
+                R|<local>/b| ->  {
+                    ^@run Unit
+                }
+            }
+
+            when (R|<local>/a|) {
+                ($subj$ is R|kotlin/String|) ->  {
+                    Int(1)
+                }
+            }
+
+        }
+        )
+    }
diff --git a/compiler/fir/analysis-tests/testData/resolve/exhaustiveness/positive/nonExhaustiveWhenWithCoercionToUnit.kt b/compiler/fir/analysis-tests/testData/resolve/exhaustiveness/positive/nonExhaustiveWhenWithCoercionToUnit.kt
new file mode 100644
index 00000000000..4e30a814d3c
--- /dev/null
+++ b/compiler/fir/analysis-tests/testData/resolve/exhaustiveness/positive/nonExhaustiveWhenWithCoercionToUnit.kt
@@ -0,0 +1,10 @@
+fun <T> run(block: () -> T): T = block()
+
+fun test(a: Any, b: Boolean) {
+    run {
+        if (b) return@run
+        when (a) {
+            is String -> 1
+        }
+    }
+}
diff --git a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticTestGenerated.java b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticTestGenerated.java
index f7da3ebcfff..6bd06b6a5e3 100644
--- a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticTestGenerated.java
+++ b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticTestGenerated.java
@@ -1459,6 +1459,12 @@ public class FirDiagnosticTestGenerated extends AbstractFirDiagnosticTest {
                 public void testMissingSealedInheritor() throws Exception {
                     runTest("compiler/fir/analysis-tests/testData/resolve/exhaustiveness/negative/missingSealedInheritor.kt");
                 }
+
+                @Test
+                @TestMetadata("nonExhaustiveWhenWithoutCoercionToUnit.kt")
+                public void testNonExhaustiveWhenWithoutCoercionToUnit() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolve/exhaustiveness/negative/nonExhaustiveWhenWithoutCoercionToUnit.kt");
+                }
             }
 
             @Nested
@@ -1517,6 +1523,12 @@ public class FirDiagnosticTestGenerated extends AbstractFirDiagnosticTest {
                 public void testExhaustiveness_sealedSubClass() throws Exception {
                     runTest("compiler/fir/analysis-tests/testData/resolve/exhaustiveness/positive/exhaustiveness_sealedSubClass.kt");
                 }
+
+                @Test
+                @TestMetadata("nonExhaustiveWhenWithCoercionToUnit.kt")
+                public void testNonExhaustiveWhenWithCoercionToUnit() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolve/exhaustiveness/positive/nonExhaustiveWhenWithCoercionToUnit.kt");
+                }
             }
         }
 
diff --git a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticsWithLightTreeTestGenerated.java b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticsWithLightTreeTestGenerated.java
index ea8708480aa..223e54c2497 100644
--- a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticsWithLightTreeTestGenerated.java
+++ b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticsWithLightTreeTestGenerated.java
@@ -1473,6 +1473,12 @@ public class FirDiagnosticsWithLightTreeTestGenerated extends AbstractFirDiagnos
                 public void testMissingSealedInheritor() throws Exception {
                     runTest("compiler/fir/analysis-tests/testData/resolve/exhaustiveness/negative/missingSealedInheritor.kt");
                 }
+
+                @Test
+                @TestMetadata("nonExhaustiveWhenWithoutCoercionToUnit.kt")
+                public void testNonExhaustiveWhenWithoutCoercionToUnit() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolve/exhaustiveness/negative/nonExhaustiveWhenWithoutCoercionToUnit.kt");
+                }
             }
 
             @Nested
@@ -1532,6 +1538,12 @@ public class FirDiagnosticsWithLightTreeTestGenerated extends AbstractFirDiagnos
                 public void testExhaustiveness_sealedSubClass() throws Exception {
                     runTest("compiler/fir/analysis-tests/testData/resolve/exhaustiveness/positive/exhaustiveness_sealedSubClass.kt");
                 }
+
+                @Test
+                @TestMetadata("nonExhaustiveWhenWithCoercionToUnit.kt")
+                public void testNonExhaustiveWhenWithCoercionToUnit() throws Exception {
+                    runTest("compiler/fir/analysis-tests/testData/resolve/exhaustiveness/positive/nonExhaustiveWhenWithCoercionToUnit.kt");
+                }
             }
         }