diff --git a/src/core/geometry_type.hpp b/src/core/geometry_type.hpp
index 4f2d9d4fcf..2c1f91abe4 100644
--- a/src/core/geometry_type.hpp
+++ b/src/core/geometry_type.hpp
@@ -215,7 +215,7 @@ struct Rect {
 	/**
 	 * Test if a point falls inside this Rect.
 	 * @param pt the point to test.
-	 * @return true iif the point falls inside the Rect.
+	 * @return true iff the point falls inside the Rect.
 	 */
 	inline bool Contains(const Point &pt) const
 	{
diff --git a/src/newgrf_object.h b/src/newgrf_object.h
index 644463674f..14200091bf 100644
--- a/src/newgrf_object.h
+++ b/src/newgrf_object.h
@@ -78,7 +78,7 @@ struct ObjectSpec {
 
 	/**
 	 * Test if this object is enabled.
-	 * @return True iif this object is enabled.
+	 * @return True iff this object is enabled.
 	 */
 	bool IsEnabled() const { return this->views > 0; }