diff --git a/glm/detail/type_vec1.inl b/glm/detail/type_vec1.inl
index 7f77f6c2..ee9460bf 100644
--- a/glm/detail/type_vec1.inl
+++ b/glm/detail/type_vec1.inl
@@ -70,7 +70,7 @@ namespace glm
 	}
 
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER T const& vec<1, T, Q>::operator[](typename vec<1, T, Q>::length_type i) const
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR_CXX14 T const& vec<1, T, Q>::operator[](typename vec<1, T, Q>::length_type i) const
 	{
 		assert(i >= 0 && i < this->length());
 		return (&x)[i];
diff --git a/glm/detail/type_vec2.hpp b/glm/detail/type_vec2.hpp
index b6ab6853..87295503 100644
--- a/glm/detail/type_vec2.hpp
+++ b/glm/detail/type_vec2.hpp
@@ -82,7 +82,7 @@ namespace glm
 		GLM_FUNC_DECL static GLM_CONSTEXPR length_type length(){return 2;}
 
 		GLM_FUNC_DECL T& operator[](length_type i);
-		GLM_FUNC_DECL T const& operator[](length_type i) const;
+		GLM_FUNC_DECL GLM_CONSTEXPR_CXX14 T const& operator[](length_type i) const;
 
 		// -- Implicit basic constructors --
 
diff --git a/glm/detail/type_vec2.inl b/glm/detail/type_vec2.inl
index 12737079..e306771a 100644
--- a/glm/detail/type_vec2.inl
+++ b/glm/detail/type_vec2.inl
@@ -88,7 +88,7 @@ namespace glm
 	}
 
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER T const& vec<2, T, Q>::operator[](typename vec<2, T, Q>::length_type i) const
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR_CXX14 T const& vec<2, T, Q>::operator[](typename vec<2, T, Q>::length_type i) const
 	{
 		assert(i >= 0 && i < this->length());
 		return (&x)[i];
diff --git a/glm/detail/type_vec3.hpp b/glm/detail/type_vec3.hpp
index 506e8a36..5fffc69a 100644
--- a/glm/detail/type_vec3.hpp
+++ b/glm/detail/type_vec3.hpp
@@ -82,7 +82,7 @@ namespace glm
 		GLM_FUNC_DECL static GLM_CONSTEXPR length_type length(){return 3;}
 
 		GLM_FUNC_DECL T & operator[](length_type i);
-		GLM_FUNC_DECL T const& operator[](length_type i) const;
+		GLM_FUNC_DECL GLM_CONSTEXPR_CXX14 T const& operator[](length_type i) const;
 
 		// -- Implicit basic constructors --
 
diff --git a/glm/detail/type_vec3.inl b/glm/detail/type_vec3.inl
index 15fd4839..8aec0ac6 100644
--- a/glm/detail/type_vec3.inl
+++ b/glm/detail/type_vec3.inl
@@ -117,7 +117,7 @@ namespace glm
 	}
 
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER T const& vec<3, T, Q>::operator[](typename vec<3, T, Q>::length_type i) const
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR_CXX14 T const& vec<3, T, Q>::operator[](typename vec<3, T, Q>::length_type i) const
 	{
 		assert(i >= 0 && i < this->length());
 		return (&x)[i];
diff --git a/glm/detail/type_vec4.hpp b/glm/detail/type_vec4.hpp
index 43395ca4..a05ac5de 100644
--- a/glm/detail/type_vec4.hpp
+++ b/glm/detail/type_vec4.hpp
@@ -85,7 +85,7 @@ namespace glm
 		GLM_FUNC_DECL static GLM_CONSTEXPR length_type length(){return 4;}
 
 		GLM_FUNC_DECL T & operator[](length_type i);
-		GLM_FUNC_DECL T const& operator[](length_type i) const;
+		GLM_FUNC_DECL GLM_CONSTEXPR_CXX14 T const& operator[](length_type i) const;
 
 		// -- Implicit basic constructors --
 
diff --git a/glm/detail/type_vec4.inl b/glm/detail/type_vec4.inl
index 972cb4e4..021f50d8 100644
--- a/glm/detail/type_vec4.inl
+++ b/glm/detail/type_vec4.inl
@@ -332,7 +332,7 @@ namespace detail
 	}
 
 	template<typename T, qualifier Q>
-	GLM_FUNC_QUALIFIER T const& vec<4, T, Q>::operator[](typename vec<4, T, Q>::length_type i) const
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR_CXX14 T const& vec<4, T, Q>::operator[](typename vec<4, T, Q>::length_type i) const
 	{
 		assert(i >= 0 && i < this->length());
 		return (&x)[i];
diff --git a/glm/ext/vec1.hpp b/glm/ext/vec1.hpp
index cbaf672c..5246a457 100644
--- a/glm/ext/vec1.hpp
+++ b/glm/ext/vec1.hpp
@@ -97,7 +97,7 @@ namespace glm
 		GLM_FUNC_DECL static GLM_CONSTEXPR length_type length(){return 1;}
 
 		GLM_FUNC_DECL T & operator[](length_type i);
-		GLM_FUNC_DECL T const& operator[](length_type i) const;
+		GLM_FUNC_DECL GLM_CONSTEXPR_CXX14 T const& operator[](length_type i) const;
 
 		// -- Implicit basic constructors --