diff --git a/glm/detail/setup.hpp b/glm/detail/setup.hpp
index f8378ee0..d14d0e25 100644
--- a/glm/detail/setup.hpp
+++ b/glm/detail/setup.hpp
@@ -62,6 +62,7 @@
 #define GLM_PLATFORM_UNIX			0x00400000
 #define GLM_PLATFORM_QNXNTO			0x00800000
 #define GLM_PLATFORM_WINCE			0x01000000
+#define GLM_PLATFORM_CYGWIN			0x02000000
 
 #ifdef GLM_FORCE_PLATFORM_UNKNOWN
 #	define GLM_PLATFORM GLM_PLATFORM_UNKNOWN
diff --git a/readme.md b/readme.md
index e637bc4b..af96182c 100644
--- a/readme.md
+++ b/readme.md
@@ -58,6 +58,7 @@ glm::mat4 camera(float Translate, glm::vec2 const & Rotate)
 - Fixed outerProduct defintions and operator signatures for mat2x4 and vec4 #475
 - Fixed eulerAngles precision error, returns NaN  #451
 - Fixed undefined reference errors #489
+- Fixed missing GLM_PLATFORM_CYGWIN declaration #495
 
 #### [GLM 0.9.7.3](https://github.com/g-truc/glm/releases/tag/0.9.7.3) - 2016-02-21
 ##### Improvements: