diff --git a/compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit/neg/1.fir.kt b/compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit/neg/1.fir.kt
new file mode 100644
index 00000000000..1cbb749a12e
--- /dev/null
+++ b/compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit/neg/1.fir.kt
@@ -0,0 +1,11 @@
+// TESTCASE NUMBER: 1
+
+val y0 = when (2) {
+    else -> if (true) {""}
+}
+
+val w:Any = TODO()
+
+val y1 = when (2) {
+    else -> if (true) {""} // false ok with coercion to Unit
+}
diff --git a/compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit/neg/1.kt b/compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit/neg/1.kt
new file mode 100644
index 00000000000..8c342ea4428
--- /dev/null
+++ b/compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit/neg/1.kt
@@ -0,0 +1,20 @@
+/*
+ * KOTLIN DIAGNOSTICS NOT LINKED SPEC TEST (NEGATIVE)
+ *
+ * SECTIONS: coercion-to-unit
+ * NUMBER: 1
+ * DESCRIPTION: Coercion to Unit error diagnostics absence
+ * ISSUES: KT-38490
+ */
+
+// TESTCASE NUMBER: 1
+
+val y0 = when (<!UNUSED_EXPRESSION!>2<!>) {
+    else -> <!INVALID_IF_AS_EXPRESSION!>if<!> (true) {""}
+}
+
+val w:Any = TODO()
+
+val y1 = when (2) {
+    else -> if (true) {""} // false ok with coercion to Unit
+}
\ No newline at end of file
diff --git a/compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit/neg/1.txt b/compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit/neg/1.txt
new file mode 100644
index 00000000000..aad34e81ff6
--- /dev/null
+++ b/compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit/neg/1.txt
@@ -0,0 +1,5 @@
+package
+
+public val w: kotlin.Any
+public val y0: kotlin.Unit
+public val y1: kotlin.Unit
diff --git a/compiler/tests-spec/tests/org/jetbrains/kotlin/spec/checkers/DiagnosticsTestSpecGenerated.java b/compiler/tests-spec/tests/org/jetbrains/kotlin/spec/checkers/DiagnosticsTestSpecGenerated.java
index 124a724ae07..b4c297196ed 100644
--- a/compiler/tests-spec/tests/org/jetbrains/kotlin/spec/checkers/DiagnosticsTestSpecGenerated.java
+++ b/compiler/tests-spec/tests/org/jetbrains/kotlin/spec/checkers/DiagnosticsTestSpecGenerated.java
@@ -5055,6 +5055,37 @@ public class DiagnosticsTestSpecGenerated extends AbstractDiagnosticsTestSpec {
             }
         }
 
+        @TestMetadata("compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class Coercion_to_unit extends AbstractDiagnosticsTestSpec {
+            private void runTest(String testDataFilePath) throws Exception {
+                KotlinTestUtils.runTest(this::doTest, this, testDataFilePath);
+            }
+
+            public void testAllFilesPresentInCoercion_to_unit() throws Exception {
+                KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
+            }
+
+            @TestMetadata("compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit/neg")
+            @TestDataPath("$PROJECT_ROOT")
+            @RunWith(JUnit3RunnerWithInners.class)
+            public static class Neg extends AbstractDiagnosticsTestSpec {
+                private void runTest(String testDataFilePath) throws Exception {
+                    KotlinTestUtils.runTest(this::doTest, this, testDataFilePath);
+                }
+
+                @TestMetadata("1.kt")
+                public void test1() throws Exception {
+                    runTest("compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit/neg/1.kt");
+                }
+
+                public void testAllFilesPresentInNeg() throws Exception {
+                    KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit/neg"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
+                }
+            }
+        }
+
         @TestMetadata("compiler/tests-spec/testData/diagnostics/notLinked/contracts")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)
diff --git a/compiler/tests-spec/tests/org/jetbrains/kotlin/spec/checkers/FirDiagnosticsTestSpecGenerated.java b/compiler/tests-spec/tests/org/jetbrains/kotlin/spec/checkers/FirDiagnosticsTestSpecGenerated.java
index 93d8604e8d6..89711c0af14 100644
--- a/compiler/tests-spec/tests/org/jetbrains/kotlin/spec/checkers/FirDiagnosticsTestSpecGenerated.java
+++ b/compiler/tests-spec/tests/org/jetbrains/kotlin/spec/checkers/FirDiagnosticsTestSpecGenerated.java
@@ -5055,6 +5055,37 @@ public class FirDiagnosticsTestSpecGenerated extends AbstractFirDiagnosticsTestS
             }
         }
 
+        @TestMetadata("compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class Coercion_to_unit extends AbstractFirDiagnosticsTestSpec {
+            private void runTest(String testDataFilePath) throws Exception {
+                KotlinTestUtils.runTest(this::doTest, this, testDataFilePath);
+            }
+
+            public void testAllFilesPresentInCoercion_to_unit() throws Exception {
+                KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
+            }
+
+            @TestMetadata("compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit/neg")
+            @TestDataPath("$PROJECT_ROOT")
+            @RunWith(JUnit3RunnerWithInners.class)
+            public static class Neg extends AbstractFirDiagnosticsTestSpec {
+                private void runTest(String testDataFilePath) throws Exception {
+                    KotlinTestUtils.runTest(this::doTest, this, testDataFilePath);
+                }
+
+                @TestMetadata("1.kt")
+                public void test1() throws Exception {
+                    runTest("compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit/neg/1.kt");
+                }
+
+                public void testAllFilesPresentInNeg() throws Exception {
+                    KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/tests-spec/testData/diagnostics/notLinked/coercion-to-unit/neg"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
+                }
+            }
+        }
+
         @TestMetadata("compiler/tests-spec/testData/diagnostics/notLinked/contracts")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)