diff --git a/03-Style.md b/03-Style.md
index ab60aaa..5e90e2b 100644
--- a/03-Style.md
+++ b/03-Style.md
@@ -103,7 +103,7 @@ Header files must contain an distinctly named include guard to avoid problems wi
 
 ```cpp
 #ifndef MYPROJECT_MYCLASS_HPP
-#define MYPROEJCT_MYCLASS_HPP
+#define MYPROJECT_MYCLASS_HPP
 
 namespace MyProject {
 class MyClass {