diff --git a/NETGenerator/NETGenerator.cs b/NETGenerator/NETGenerator.cs
index 2390dc7b8..3333e6422 100644
--- a/NETGenerator/NETGenerator.cs
+++ b/NETGenerator/NETGenerator.cs
@@ -10399,7 +10399,9 @@ namespace PascalABCCompiler.NETGenerator
             il.Emit(OpCodes.Stloc, lb);
             il.Emit(OpCodes.Call, _monitor_enter);
             il.BeginExceptionBlock();
+            bool safe_block = EnterSafeBlock();
             ConvertStatement(value.Body);
+            LeaveSafeBlock(safe_block);
             il.BeginFinallyBlock();
             il.Emit(OpCodes.Ldloc, lb);
             il.Emit(OpCodes.Call, _monitor_exit);
diff --git a/TestSuite/lock1.pas b/TestSuite/lock1.pas
new file mode 100644
index 000000000..c9844baf8
--- /dev/null
+++ b/TestSuite/lock1.pas
@@ -0,0 +1,54 @@
+type t1 = class end;//любой ссылочный тип
+
+var i: integer;
+
+procedure p1;
+begin
+  lock new t1 do
+  begin
+    i := 1;
+    exit;
+  end;
+end;
+
+procedure p2;
+begin
+  loop 1 do
+    lock new t1 do
+    begin
+      i := 2;
+      continue;
+    end;
+end;
+
+procedure p3;
+begin
+  loop 1 do
+    lock new t1 do
+    begin
+      i := 3;
+      break;
+    end;
+end;
+
+procedure p4;
+label l1;
+begin
+  lock new t1 do
+  begin
+    i := 4;
+    goto l1;
+  end;
+  l1:
+end;
+
+begin
+  p1;
+  assert(i = 1);
+  p2;
+  assert(i = 2);
+  p3;
+  assert(i = 3);
+  p4;
+  assert(i = 4);
+end.
\ No newline at end of file