diff --git a/include/assimp/vector3.h b/include/assimp/vector3.h
index 9edaf5bf6..a4c33b194 100644
--- a/include/assimp/vector3.h
+++ b/include/assimp/vector3.h
@@ -88,6 +88,7 @@ public:
 	// comparison
 	bool operator== (const aiVector3t& other) const;
 	bool operator!= (const aiVector3t& other) const;
+	bool operator < (const aiVector3t& other) const;
 
 	bool Equal(const aiVector3t& other, TReal epsilon = 1e-6) const;
 
diff --git a/include/assimp/vector3.inl b/include/assimp/vector3.inl
index 93f317645..f69bea9a6 100644
--- a/include/assimp/vector3.inl
+++ b/include/assimp/vector3.inl
@@ -159,6 +159,11 @@ AI_FORCE_INLINE bool aiVector3t<TReal>::Equal(const aiVector3t<TReal>& other, TR
 }
 // ------------------------------------------------------------------------------------------------
 template <typename TReal>
+AI_FORCE_INLINE bool aiVector3t<TReal>::operator < (const aiVector3t<TReal>& other) const {
+	return x != other.x ? x < other.x : y != other.y ? y < other.y : z < other.z;
+}
+// ------------------------------------------------------------------------------------------------
+template <typename TReal>
 AI_FORCE_INLINE const aiVector3t<TReal> aiVector3t<TReal>::SymMul(const aiVector3t<TReal>& o) {
 	return aiVector3t<TReal>(x*o.x,y*o.y,z*o.z);
 }