diff --git a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java
index 67dba8d9f27..ca34aebe711 100644
--- a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java
+++ b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java
@@ -996,6 +996,12 @@ public class DiagnosisCompilerTestFE10TestdataTestGenerated extends AbstractDiag
                 runTest("compiler/testData/diagnostics/tests/annotations/AmbigiousAnnotationConstructor.kt");
             }
 
+            @Test
+            @TestMetadata("AnnotatedBlock.kt")
+            public void testAnnotatedBlock() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/annotations/AnnotatedBlock.kt");
+            }
+
             @Test
             @TestMetadata("AnnotatedConstructor.kt")
             public void testAnnotatedConstructor() throws Exception {
diff --git a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java
index 8f162dde7fe..556d9698867 100644
--- a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java
+++ b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java
@@ -996,6 +996,12 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                 runTest("compiler/testData/diagnostics/tests/annotations/AmbigiousAnnotationConstructor.kt");
             }
 
+            @Test
+            @TestMetadata("AnnotatedBlock.kt")
+            public void testAnnotatedBlock() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/annotations/AnnotatedBlock.kt");
+            }
+
             @Test
             @TestMetadata("AnnotatedConstructor.kt")
             public void testAnnotatedConstructor() throws Exception {
diff --git a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsWithLightTreeTestGenerated.java b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsWithLightTreeTestGenerated.java
index 76ba3f4a97f..9cdb0e13770 100644
--- a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsWithLightTreeTestGenerated.java
+++ b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsWithLightTreeTestGenerated.java
@@ -996,6 +996,12 @@ public class FirOldFrontendDiagnosticsWithLightTreeTestGenerated extends Abstrac
                 runTest("compiler/testData/diagnostics/tests/annotations/AmbigiousAnnotationConstructor.kt");
             }
 
+            @Test
+            @TestMetadata("AnnotatedBlock.kt")
+            public void testAnnotatedBlock() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/annotations/AnnotatedBlock.kt");
+            }
+
             @Test
             @TestMetadata("AnnotatedConstructor.kt")
             public void testAnnotatedConstructor() throws Exception {
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirExpressionAnnotationChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirExpressionAnnotationChecker.kt
index aa07ecd5302..1089faa19e0 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirExpressionAnnotationChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirExpressionAnnotationChecker.kt
@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.fir.analysis.checkers.expression
 
 import org.jetbrains.kotlin.KtFakeSourceElementKind
+import org.jetbrains.kotlin.KtRealSourceElementKind
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationUseSiteTarget
 import org.jetbrains.kotlin.descriptors.annotations.KotlinTarget
 import org.jetbrains.kotlin.fir.analysis.checkers.checkRepeatedAnnotation
@@ -29,7 +30,8 @@ object FirExpressionAnnotationChecker : FirBasicExpressionChecker() {
         // See KT-33658 about annotations on non-expression statements
         if (expression is FirDeclaration ||
             expression !is FirExpression ||
-            expression is FirBlock && expression.source?.kind == KtFakeSourceElementKind.DesugaredForLoop
+            expression is FirBlock && (expression.source?.kind == KtRealSourceElementKind ||
+                    expression.source?.kind == KtFakeSourceElementKind.DesugaredForLoop)
         ) return
 
         val annotations = expression.annotations
diff --git a/compiler/testData/diagnostics/tests/annotations/AnnotatedBlock.fir.txt b/compiler/testData/diagnostics/tests/annotations/AnnotatedBlock.fir.txt
new file mode 100644
index 00000000000..4b18b936f46
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/annotations/AnnotatedBlock.fir.txt
@@ -0,0 +1,28 @@
+FILE: AnnotatedBlock.kt
+    public final annotation class Ann : R|kotlin/Annotation| {
+        public constructor(): R|Ann| {
+            super<R|kotlin/Any|>()
+        }
+
+    }
+    public final annotation class Ann2 : R|kotlin/Annotation| {
+        public constructor(): R|Ann2| {
+            super<R|kotlin/Any|>()
+        }
+
+    }
+    public final fun test(x: R|kotlin/String?|): R|kotlin/Unit| {
+        when () {
+            !=(R|<local>/x|, Null(null)) -> @R|Ann|() @R|Ann2|()  {
+                Q|kotlin/Unit|
+            }
+        }
+
+        when () {
+            !=(R|<local>/x|, Null(null)) ->  {
+                @R|Ann|() @R|Ann2|() Q|kotlin/Unit|
+            }
+        }
+
+        @R|Ann|() @R|Ann2|() R|<local>/x|
+    }
diff --git a/compiler/testData/diagnostics/tests/annotations/AnnotatedBlock.kt b/compiler/testData/diagnostics/tests/annotations/AnnotatedBlock.kt
new file mode 100644
index 00000000000..7b30f955d2e
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/annotations/AnnotatedBlock.kt
@@ -0,0 +1,10 @@
+// FIR_IDENTICAL
+// FIR_DUMP
+// ISSUE: KT-52175
+
+annotation class Ann
+
+fun test(x: String?) {
+    if (x != null)
+        @Ann() { Unit }
+}
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/annotations/AnnotatedBlock.txt b/compiler/testData/diagnostics/tests/annotations/AnnotatedBlock.txt
new file mode 100644
index 00000000000..e41d31997ba
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/annotations/AnnotatedBlock.txt
@@ -0,0 +1,10 @@
+package
+
+public fun test(/*0*/ x: kotlin.String?): kotlin.Unit
+
+public final annotation class Ann : kotlin.Annotation {
+    public constructor Ann()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
diff --git a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java
index c438b7f364a..6c9d2da3bb4 100644
--- a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java
+++ b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java
@@ -996,6 +996,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 runTest("compiler/testData/diagnostics/tests/annotations/AmbigiousAnnotationConstructor.kt");
             }
 
+            @Test
+            @TestMetadata("AnnotatedBlock.kt")
+            public void testAnnotatedBlock() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/annotations/AnnotatedBlock.kt");
+            }
+
             @Test
             @TestMetadata("AnnotatedConstructor.kt")
             public void testAnnotatedConstructor() throws Exception {