diff --git a/src/Microsoft.OData.Core/UriParser/ExpressionLexer.cs b/src/Microsoft.OData.Core/UriParser/ExpressionLexer.cs
index 020456ce51..407beaa770 100644
--- a/src/Microsoft.OData.Core/UriParser/ExpressionLexer.cs
+++ b/src/Microsoft.OData.Core/UriParser/ExpressionLexer.cs
@@ -686,15 +686,9 @@ protected virtual ExpressionToken NextTokenImplementation(out Exception error)
                         string leftToken = ExpressionText.Substring(start, this.textPos - start);
 
 
-                        t = this.parsingFunctionParameters
-                            && !(leftToken[0] == UriQueryConstants.AnnotationPrefix
-                                && leftToken.Contains("."))
-                            ? ExpressionTokenKind.ParameterAlias : ExpressionTokenKind.Identifier;
-
-                        //                        t = this.parsingFunctionParameters
-                        //                            && !(this.ExpressionText[0] == UriQueryConstants.AnnotationPrefix
-                        //                                && this.ExpressionText.Contains("."))
-                        //                            ? ExpressionTokenKind.ParameterAlias : ExpressionTokenKind.Identifier;
+                        t = this.parsingFunctionParameters && !leftToken.Contains(".")
+                            ? ExpressionTokenKind.ParameterAlias
+                            : ExpressionTokenKind.Identifier;
                         break;
                     }
 
diff --git a/test/FunctionalTests/Microsoft.OData.Core.Tests/UriParser/ExpressionLexerTests.cs b/test/FunctionalTests/Microsoft.OData.Core.Tests/UriParser/ExpressionLexerTests.cs
index 67a151baef..4f3dda68f3 100644
--- a/test/FunctionalTests/Microsoft.OData.Core.Tests/UriParser/ExpressionLexerTests.cs
+++ b/test/FunctionalTests/Microsoft.OData.Core.Tests/UriParser/ExpressionLexerTests.cs
@@ -707,10 +707,18 @@ public void ExpressionLexerShouldParseValidAliasCorrectly()
         [Fact]
         public void ExpressionLexerShouldParseValidAliasWithDotInExpressionCorrectly()
         {
-            ValidateTokenSequence("@foo eq 1.23", true /*parsingFunctionParameters*/,
-                ParameterAliasToken("@foo"),
-                IdentifierToken("eq"),
-                SingleLiteralToken("1.23"));
+            foreach (string expr in new string[]
+                {
+                    "@foo eq 1.23",
+                    "  @foo  eq  1.23  " // with arbitrary paddings.
+                }
+            )
+            {
+                ValidateTokenSequence(expr, true /*parsingFunctionParameters*/,
+                    ParameterAliasToken("@foo"),
+                    IdentifierToken("eq"),
+                    SingleLiteralToken("1.23"));
+            }
         }
 
         [Fact]