diff --git a/samples/lambda.wes b/samples/lambda.wes
index ed93346..dcd61f0 100644
--- a/samples/lambda.wes
+++ b/samples/lambda.wes
@@ -1,3 +1,2 @@
-var add_them = function(x, y) { x + y }
-//print(add_them(3, 4))
-print(7)
+var add2 = function(x, y) { x + y }
+print(add2(3, 4))
diff --git a/wesley/wesley_engine.hpp b/wesley/wesley_engine.hpp
index 84df81f..4171746 100644
--- a/wesley/wesley_engine.hpp
+++ b/wesley/wesley_engine.hpp
@@ -81,7 +81,7 @@ public:
         lexer.set_multiline_comment(Pattern("/\\*", TokenType::Comment), Pattern("\\*/", TokenType::Comment));
         lexer.set_singleline_comment(Pattern("//", TokenType::Comment));
 
-        lexer << Pattern("[A-Za-z_]+", TokenType::Identifier);
+        lexer << Pattern("[A-Za-z_][A-Za-z_0-9]*", TokenType::Identifier);
         lexer << Pattern("[0-9]+\\.[0-9]+", TokenType::Real_Number);
         lexer << Pattern("[0-9]+", TokenType::Integer);
         lexer << Pattern("[!@#$%^&*|\\-+=<>.]+|/[!@#$%^&|\\-+=<>]*", TokenType::Operator);