diff --git a/glm/detail/type_vec4.hpp b/glm/detail/type_vec4.hpp
index 4ecfeee2..f08bd343 100644
--- a/glm/detail/type_vec4.hpp
+++ b/glm/detail/type_vec4.hpp
@@ -143,18 +143,36 @@ namespace glm
 		GLM_FUNC_DECL GLM_CONSTEXPR_CTOR vec(vec<2, A, P> const& _xy, B _z, C _w);
 		/// Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
 		template<typename A, typename B, typename C, qualifier P>
+		GLM_FUNC_DECL GLM_CONSTEXPR_CTOR vec(vec<2, A, P> const& _xy, vec<1, B, P> const& _z, C _w);
+		/// Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
+		template<typename A, typename B, typename C, qualifier P>
+		GLM_FUNC_DECL GLM_CONSTEXPR_CTOR vec(vec<2, A, P> const& _xy, B _z, vec<1, C, P> const& _w);
+		/// Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
+		template<typename A, typename B, typename C, qualifier P>
 		GLM_FUNC_DECL GLM_CONSTEXPR_CTOR vec(vec<2, A, P> const& _xy, vec<1, B, P> const& _z, vec<1, C, P> const& _w);
 		/// Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
 		template<typename A, typename B, typename C, qualifier P>
 		GLM_FUNC_DECL GLM_CONSTEXPR_CTOR vec(A _x, vec<2, B, P> const& _yz, C _w);
 		/// Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
 		template<typename A, typename B, typename C, qualifier P>
+		GLM_FUNC_DECL GLM_CONSTEXPR_CTOR vec(vec<1, A, P> const& _x, vec<2, B, P> const& _yz, C _w);
+		/// Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
+		template<typename A, typename B, typename C, qualifier P>
+		GLM_FUNC_DECL GLM_CONSTEXPR_CTOR vec(A _x, vec<2, B, P> const& _yz, vec<1, C, P> const& _w);
+		/// Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
+		template<typename A, typename B, typename C, qualifier P>
 		GLM_FUNC_DECL GLM_CONSTEXPR_CTOR vec(vec<1, A, P> const& _x, vec<2, B, P> const& _yz, vec<1, C, P> const& _w);
 		/// Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
 		template<typename A, typename B, typename C, qualifier P>
 		GLM_FUNC_DECL GLM_CONSTEXPR_CTOR vec(A _x, B _y, vec<2, C, P> const& _zw);
 		/// Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
 		template<typename A, typename B, typename C, qualifier P>
+		GLM_FUNC_DECL GLM_CONSTEXPR_CTOR vec(vec<1, A, P> const& _x, B _y, vec<2, C, P> const& _zw);
+		/// Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
+		template<typename A, typename B, typename C, qualifier P>
+		GLM_FUNC_DECL GLM_CONSTEXPR_CTOR vec(A _x, vec<1, B, P> const& _y, vec<2, C, P> const& _zw);
+		/// Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
+		template<typename A, typename B, typename C, qualifier P>
 		GLM_FUNC_DECL GLM_CONSTEXPR_CTOR vec(vec<1, A, P> const& _x, vec<1, B, P> const& _y, vec<2, C, P> const& _zw);
 		/// Explicit conversions (From section 5.4.1 Conversion and scalar constructors of GLSL 1.30.08 specification)
 		template<typename A, typename B, qualifier P>
diff --git a/glm/detail/type_vec4.inl b/glm/detail/type_vec4.inl
index 7b069f12..1c040599 100644
--- a/glm/detail/type_vec4.inl
+++ b/glm/detail/type_vec4.inl
@@ -349,6 +349,24 @@ namespace detail
 		, w(static_cast<T>(_w))
 	{}
 
+	template<typename T, qualifier Q>
+	template<typename A, typename B, typename C, qualifier P>
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR_CTOR vec<4, T, Q>::vec(vec<2, A, P> const& _xy, vec<1, B, P> const& _z, C _w)
+		: x(static_cast<T>(_xy.x))
+		, y(static_cast<T>(_xy.y))
+		, z(static_cast<T>(_z.x))
+		, w(static_cast<T>(_w))
+	{}
+
+	template<typename T, qualifier Q>
+	template<typename A, typename B, typename C, qualifier P>
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR_CTOR vec<4, T, Q>::vec(vec<2, A, P> const& _xy, B _z, vec<1, C, P> const& _w)
+		: x(static_cast<T>(_xy.x))
+		, y(static_cast<T>(_xy.y))
+		, z(static_cast<T>(_z))
+		, w(static_cast<T>(_w.x))
+	{}
+
 	template<typename T, qualifier Q>
 	template<typename A, typename B, typename C, qualifier P>
 	GLM_FUNC_QUALIFIER GLM_CONSTEXPR_CTOR vec<4, T, Q>::vec(vec<2, A, P> const& _xy, vec<1, B, P> const& _z, vec<1, C, P> const& _w)
@@ -367,6 +385,24 @@ namespace detail
 		, w(static_cast<T>(_w))
 	{}
 
+	template<typename T, qualifier Q>
+	template<typename A, typename B, typename C, qualifier P>
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR_CTOR vec<4, T, Q>::vec(vec<1, A, P> const& _x, vec<2, B, P> const& _yz, C _w)
+		: x(static_cast<T>(_x.x))
+		, y(static_cast<T>(_yz.x))
+		, z(static_cast<T>(_yz.y))
+		, w(static_cast<T>(_w))
+	{}
+
+	template<typename T, qualifier Q>
+	template<typename A, typename B, typename C, qualifier P>
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR_CTOR vec<4, T, Q>::vec(A _x, vec<2, B, P> const& _yz, vec<1, C, P> const& _w)
+		: x(static_cast<T>(_x))
+		, y(static_cast<T>(_yz.x))
+		, z(static_cast<T>(_yz.y))
+		, w(static_cast<T>(_w.x))
+	{}
+
 	template<typename T, qualifier Q>
 	template<typename A, typename B, typename C, qualifier P>
 	GLM_FUNC_QUALIFIER GLM_CONSTEXPR_CTOR vec<4, T, Q>::vec(vec<1, A, P> const& _x, vec<2, B, P> const& _yz, vec<1, C, P> const& _w)
@@ -385,6 +421,24 @@ namespace detail
 		, w(static_cast<T>(_zw.y))
 	{}
 
+	template<typename T, qualifier Q>
+	template<typename A, typename B, typename C, qualifier P>
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR_CTOR vec<4, T, Q>::vec(vec<1, A, P> const& _x, B _y, vec<2, C, P> const& _zw)
+		: x(static_cast<T>(_x.x))
+		, y(static_cast<T>(_y))
+		, z(static_cast<T>(_zw.x))
+		, w(static_cast<T>(_zw.y))
+	{}
+
+	template<typename T, qualifier Q>
+	template<typename A, typename B, typename C, qualifier P>
+	GLM_FUNC_QUALIFIER GLM_CONSTEXPR_CTOR vec<4, T, Q>::vec(A _x, vec<1, B, P> const& _y, vec<2, C, P> const& _zw)
+		: x(static_cast<T>(_x))
+		, y(static_cast<T>(_y.x))
+		, z(static_cast<T>(_zw.x))
+		, w(static_cast<T>(_zw.y))
+	{}
+
 	template<typename T, qualifier Q>
 	template<typename A, typename B, typename C, qualifier P>
 	GLM_FUNC_QUALIFIER GLM_CONSTEXPR_CTOR vec<4, T, Q>::vec(vec<1, A, P> const& _x, vec<1, B, P> const& _y, vec<2, C, P> const& _zw)
diff --git a/readme.md b/readme.md
index 8593f102..148c114e 100644
--- a/readme.md
+++ b/readme.md
@@ -55,6 +55,9 @@ glm::mat4 camera(float Translate, glm::vec2 const& Rotate)
 #### Features:
 - Added bitfieldDeinterleave to GTC_bitfield
 
+#### Improvements:
+- Added missing vec1 based constructors
+
 #### Fixes:
 - Fixed build problems due to printf and std::clock_t #778
 - Fixed int mod
diff --git a/test/core/core_type_vec4.cpp b/test/core/core_type_vec4.cpp
index 438c1f08..bc33f5f1 100644
--- a/test/core/core_type_vec4.cpp
+++ b/test/core/core_type_vec4.cpp
@@ -252,6 +252,77 @@ static int test_vec4_ctor()
 		Error += glm::all(glm::equal(V, O)) ? 0 : 1;
 	}
 
+	{
+		glm::vec1 const v1_0(1.0f);
+		glm::vec1 const v1_1(2.0f);
+		glm::vec1 const v1_2(3.0f);
+		glm::vec1 const v1_3(4.0f);
+
+		glm::vec2 const v2_0(1.0f, 2.0f);
+		glm::vec2 const v2_1(2.0f, 3.0f);
+		glm::vec2 const v2_2(3.0f, 4.0f);
+
+		glm::vec3 const v3_0(1.0f, 2.0f, 3.0f);
+		glm::vec3 const v3_1(2.0f, 3.0f, 4.0f);
+
+		glm::vec4 const O(1.0f, 2.0, 3.0f, 4.0);
+
+		glm::vec4 const A(v1_0, v1_1, v2_2);
+		Error += glm::all(glm::equal(A, O)) ? 0 : 1;
+
+		glm::vec4 const B(1.0f, 2.0f, v2_2);
+		Error += glm::all(glm::equal(B, O)) ? 0 : 1;
+
+		glm::vec4 const C(v1_0, 2.0f, v2_2);
+		Error += glm::all(glm::equal(C, O)) ? 0 : 1;
+
+		glm::vec4 const D(1.0f, v1_1, v2_2);
+		Error += glm::all(glm::equal(D, O)) ? 0 : 1;
+
+		glm::vec4 const E(v2_0, v1_2, v1_3);
+		Error += glm::all(glm::equal(E, O)) ? 0 : 1;
+
+		glm::vec4 const F(v2_0, 3.0, v1_3);
+		Error += glm::all(glm::equal(F, O)) ? 0 : 1;
+
+		glm::vec4 const G(v2_0, v1_2, 4.0);
+		Error += glm::all(glm::equal(G, O)) ? 0 : 1;
+
+		glm::vec4 const H(v2_0, 3.0f, 4.0);
+		Error += glm::all(glm::equal(H, O)) ? 0 : 1;
+	}
+
+	{
+		glm::vec1 const v1_0(1.0f);
+		glm::vec1 const v1_1(2.0f);
+		glm::vec1 const v1_2(3.0f);
+		glm::vec1 const v1_3(4.0f);
+
+		glm::vec2 const v2_0(1.0f, 2.0f);
+		glm::vec2 const v2_1(2.0f, 3.0f);
+		glm::vec2 const v2_2(3.0f, 4.0f);
+
+		glm::vec3 const v3_0(1.0f, 2.0f, 3.0f);
+		glm::vec3 const v3_1(2.0f, 3.0f, 4.0f);
+
+		glm::vec4 const O(1.0f, 2.0, 3.0f, 4.0);
+
+		glm::vec4 const A(v1_0, v2_0, v1_3);
+		Error += glm::all(glm::equal(A, O)) ? 0 : 1;
+
+		glm::vec4 const B(v1_0, v2_0, 4.0);
+		Error += glm::all(glm::equal(B, O)) ? 0 : 1;
+
+		glm::vec4 const C(1.0, v2_0, v1_3);
+		Error += glm::all(glm::equal(C, O)) ? 0 : 1;
+
+		glm::vec4 const D(1.0f, v2_0, 4.0);
+		Error += glm::all(glm::equal(D, O)) ? 0 : 1;
+
+		glm::vec4 const E(1.0, v2_0, 4.0f);
+		Error += glm::all(glm::equal(E, O)) ? 0 : 1;
+	}
+
 	return Error;
 }