diff --git a/src/NReco.LambdaParser.Tests/LambdaParserTests.cs b/src/NReco.LambdaParser.Tests/LambdaParserTests.cs
index dff729b..a35bd69 100644
--- a/src/NReco.LambdaParser.Tests/LambdaParserTests.cs
+++ b/src/NReco.LambdaParser.Tests/LambdaParserTests.cs
@@ -43,6 +43,9 @@ public void Eval() {
 
 			Assert.Equal(3M, lambdaParser.Eval("1+2", varContext) );
 			Assert.Equal(6M, lambdaParser.Eval("1+2+3", varContext));
+			Assert.Equal(6M, lambdaParser.Eval("0x1+0x02+0x003+0", varContext));
+			Assert.Equal(276M, lambdaParser.Eval("0xFF+0x0A+0x0B", varContext));
+
 			Assert.Equal("b{0}_", lambdaParser.Eval("\"b{0}_\"", varContext));
 
 			Assert.Equal(3M, lambdaParser.Eval("(1+(3-1)*4)/3", varContext));
diff --git a/src/NReco.LambdaParser/Linq/LambdaParser.cs b/src/NReco.LambdaParser/Linq/LambdaParser.cs
index 8061f10..e7b4a10 100644
--- a/src/NReco.LambdaParser/Linq/LambdaParser.cs
+++ b/src/NReco.LambdaParser/Linq/LambdaParser.cs
@@ -157,8 +157,15 @@ protected Lexem ReadLexem(string s, int startIdx) {
 					if (lexem.Type == LexemType.Unknown)
 						lexem.Type = LexemType.Name;
 				} else if (Char.IsDigit(s[lexem.End])) {
-					if (lexem.Type == LexemType.Unknown)
-						lexem.Type = LexemType.NumberConstant;
+                    if (lexem.Type == LexemType.Unknown) {
+                        if ((lexem.End + 1) < s.Length && s[lexem.End] == '0' && s[lexem.End + 1] == 'x') {
+                            lexem.End++;
+                            lexem.Type = LexemType.HexNumberConstant;
+                        }
+                        else {
+                            lexem.Type = LexemType.NumberConstant;
+                        }
+                    }
 				} else if (Array.IndexOf(specialNameChars, s[lexem.End]) >= 0) {
 					if (lexem.Type == LexemType.Unknown || lexem.Type==LexemType.Name) {
 						lexem.Type = LexemType.Name;
@@ -559,7 +566,16 @@ protected ParseResult ParseValue(string expr, int start) {
 				return new ParseResult() { 
 					End = lexem.End, 
 					Expr = Expression.Constant(new LambdaParameterWrapper( numConst, Comparer) ) };
-			} else if (lexem.Type == LexemType.StringConstant) {
+            } else if (lexem.Type == LexemType.HexNumberConstant) {
+                int numConst;
+                if (!Int32.TryParse(lexem.GetValue(), NumberStyles.HexNumber, CultureInfo.InvariantCulture, out numConst))
+                {
+                    throw new Exception(String.Format("Invalid number: {0}", lexem.GetValue()));
+                }
+                return new ParseResult() {
+                    End = lexem.End,
+                    Expr = Expression.Constant(new LambdaParameterWrapper( numConst, Comparer) ) };
+            } else if (lexem.Type == LexemType.StringConstant) {
 				return new ParseResult() { 
 					End = lexem.End, 
 					Expr = Expression.Constant( new LambdaParameterWrapper( lexem.GetValue(), Comparer) ) };
@@ -650,6 +666,7 @@ protected enum LexemType {
 			Delimiter,
 			StringConstant,
 			NumberConstant,
+            HexNumberConstant,
 			Stop
 		}
 
@@ -666,7 +683,9 @@ public string GetValue() {
 					rawValue = Expr.Substring(Start, End-Start).Trim();
 					if (Type==LexemType.StringConstant) {
 						rawValue = rawValue.Substring(1, rawValue.Length-2).Replace( "\"\"", "\"" ); 
-					}
+					} else if (Type == LexemType.HexNumberConstant) {
+                        rawValue = rawValue.Replace("0x", "");
+                    }
 				}
 				return rawValue;
 			}