diff --git a/glm/ext/matrix_projection.inl b/glm/ext/matrix_projection.inl
index 8b4eea98..2f2c196a 100644
--- a/glm/ext/matrix_projection.inl
+++ b/glm/ext/matrix_projection.inl
@@ -35,10 +35,11 @@ namespace glm
 	template<typename T, typename U, qualifier Q>
 	GLM_FUNC_QUALIFIER vec<3, T, Q> project(vec<3, T, Q> const& obj, mat<4, 4, T, Q> const& model, mat<4, 4, T, Q> const& proj, vec<4, U, Q> const& viewport)
 	{
-		if(GLM_CONFIG_CLIP_CONTROL & GLM_CLIP_CONTROL_ZO_BIT)
+#		if GLM_CONFIG_CLIP_CONTROL & GLM_CLIP_CONTROL_ZO_BIT
 			return projectZO(obj, model, proj, viewport);
-		else
+#		else
 			return projectNO(obj, model, proj, viewport);
+#		endif
 	}
 
 	template<typename T, typename U, qualifier Q>
@@ -77,10 +78,11 @@ namespace glm
 	template<typename T, typename U, qualifier Q>
 	GLM_FUNC_QUALIFIER vec<3, T, Q> unProject(vec<3, T, Q> const& win, mat<4, 4, T, Q> const& model, mat<4, 4, T, Q> const& proj, vec<4, U, Q> const& viewport)
 	{
-		if(GLM_CONFIG_CLIP_CONTROL & GLM_CLIP_CONTROL_ZO_BIT)
+#		if GLM_CONFIG_CLIP_CONTROL & GLM_CLIP_CONTROL_ZO_BIT
 			return unProjectZO(win, model, proj, viewport);
-		else
+#		else
 			return unProjectNO(win, model, proj, viewport);
+#		endif
 	}
 
 	template<typename T, qualifier Q, typename U>