diff --git a/clients/cliptest.c b/clients/cliptest.c
index 0fd302274..f9dfc2e69 100644
--- a/clients/cliptest.c
+++ b/clients/cliptest.c
@@ -193,7 +193,7 @@ clip_quad(struct gl_quad *quad, pixman_box32_t *surf_rect,
 	/* Then, use a general polygon clipping algorithm to clip the quad with
 	 * each side of the surface rect. The algorithm is Sutherland-Hodgman,
 	 * as explained in
-	 * http://www.codeguru.com/cpp/misc/misc/graphics/article.php/c8965/Polygon-Clipping.htm
+	 * https://www.codeguru.com/cplusplus/polygon-clipping/
 	 * but without looking at any of that code.
 	 */
 	n = clip_transformed(&ctx, &quad->vertices, vertices);
diff --git a/libweston/renderer-gl/gl-renderer.c b/libweston/renderer-gl/gl-renderer.c
index 9fb814829..06b85d9b4 100644
--- a/libweston/renderer-gl/gl-renderer.c
+++ b/libweston/renderer-gl/gl-renderer.c
@@ -521,7 +521,7 @@ clip_quad(struct gl_quad *quad, pixman_box32_t *surf_rect,
 	/* Then, use a general polygon clipping algorithm to clip the quad with
 	 * each side of the surface rect. The algorithm is Sutherland-Hodgman,
 	 * as explained in
-	 * http://www.codeguru.com/cpp/misc/misc/graphics/article.php/c8965/Polygon-Clipping.htm
+	 * https://www.codeguru.com/cplusplus/polygon-clipping/
 	 * but without looking at any of that code.
 	 */
 	n = clip_transformed(&ctx, &quad->vertices, vertices);
diff --git a/libweston/vertex-clipping.c b/libweston/vertex-clipping.c
index aed20a216..98faa3cd2 100644
--- a/libweston/vertex-clipping.c
+++ b/libweston/vertex-clipping.c
@@ -32,7 +32,7 @@
 WESTON_EXPORT_FOR_TESTS float
 float_difference(float a, float b)
 {
-	/* http://www.altdevblogaday.com/2012/02/22/comparing-floating-point-numbers-2012-edition/ */
+	/* https://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/ */
 	static const float max_diff = 4.0f * FLT_MIN;
 	static const float max_rel_diff = 4.0e-5;
 	float diff = a - b;