diff --git a/glm/gtc/matrix_transform.inl b/glm/gtc/matrix_transform.inl
index 2245a4f9..790ecf55 100644
--- a/glm/gtc/matrix_transform.inl
+++ b/glm/gtc/matrix_transform.inl
@@ -236,7 +236,13 @@ namespace glm
 		valType const & zFar
 	)
 	{
-		valType range = tan(radians(fovy / valType(2))) * zNear;	
+#ifdef GLM_FORCE_RADIANS
+		valType const rad = fov;
+#else
+		valType const rad = glm::radians(fov);
+#endif
+        
+		valType range = tan(radians(rad / valType(2))) * zNear;	
 		valType left = -range * aspect;
 		valType right = range * aspect;
 		valType bottom = -range;