diff --git a/src/OneScript.Language/SyntaxAnalysis/DefaultBslParser.cs b/src/OneScript.Language/SyntaxAnalysis/DefaultBslParser.cs
index 28ed3f149..75ac1439d 100644
--- a/src/OneScript.Language/SyntaxAnalysis/DefaultBslParser.cs
+++ b/src/OneScript.Language/SyntaxAnalysis/DefaultBslParser.cs
@@ -711,8 +711,15 @@ private void BuildComplexStructureStatement()
                     BuildGotoOperator();
                     break;
                 default:
-                    var expected = _tokenStack.Peek();
-                    AddError(LocalizedErrors.TokenExpected(expected));
+                    if (LanguageDef.IsBuiltInFunction(_lastExtractedLexem.Token))
+                    {
+                        AddError(LocalizedErrors.UseBuiltInFunctionAsProcedure());
+                    }
+                    else
+                    {
+                        var expected = _tokenStack.Peek();
+                        AddError(LocalizedErrors.TokenExpected(expected));
+                    }
                     break;
             }
         }