diff --git a/include/Nazara/Math/EulerAngles.hpp b/include/Nazara/Math/EulerAngles.hpp
index 6b6cabc2d..73f86e25f 100644
--- a/include/Nazara/Math/EulerAngles.hpp
+++ b/include/Nazara/Math/EulerAngles.hpp
@@ -43,8 +43,8 @@ template<typename T> class NzEulerAngles
 		/*NzEulerAngles operator*(const NzEulerAngles& angles) const;
 		NzEulerAngles operator/(const NzEulerAngles& angles) const;*/
 
-		NzEulerAngles operator+=(const NzEulerAngles& angles);
-		NzEulerAngles operator-=(const NzEulerAngles& angles);
+		NzEulerAngles& operator+=(const NzEulerAngles& angles);
+		NzEulerAngles& operator-=(const NzEulerAngles& angles);
 		/*NzEulerAngles operator*=(const NzEulerAngles& angles);
 		NzEulerAngles operator/=(const NzEulerAngles& angles);*/
 
diff --git a/include/Nazara/Math/EulerAngles.inl b/include/Nazara/Math/EulerAngles.inl
index a085d99cf..af9f8e521 100644
--- a/include/Nazara/Math/EulerAngles.inl
+++ b/include/Nazara/Math/EulerAngles.inl
@@ -123,7 +123,7 @@ NzEulerAngles<T> NzEulerAngles<T>::operator-(const NzEulerAngles& angles) const
 }
 
 template<typename T>
-NzEulerAngles<T> NzEulerAngles<T>::operator+=(const NzEulerAngles& angles)
+NzEulerAngles<T>& NzEulerAngles<T>::operator+=(const NzEulerAngles& angles)
 {
 	pitch += angles.pitch;
 	yaw += angles.yaw;
@@ -133,7 +133,7 @@ NzEulerAngles<T> NzEulerAngles<T>::operator+=(const NzEulerAngles& angles)
 }
 
 template<typename T>
-NzEulerAngles<T> NzEulerAngles<T>::operator-=(const NzEulerAngles& angles)
+NzEulerAngles<T>& NzEulerAngles<T>::operator-=(const NzEulerAngles& angles)
 {
 	pitch -= angles.pitch;
 	yaw -= angles.yaw;