diff --git a/org/testdata/captions.html b/org/testdata/captions.html
index a964c43..42eaedd 100644
--- a/org/testdata/captions.html
+++ b/org/testdata/captions.html
@@ -12,7 +12,7 @@ captioned soure block
 </figcaption>
 </figure>
 <figure>
-<img src="http://placekitten.com/200/200#.png" alt="http://placekitten.com/200/200#.png" title="http://placekitten.com/200/200#.png" /><figcaption>
+<img src="https://placekitten.com/200/200#.png" alt="https://placekitten.com/200/200#.png" title="https://placekitten.com/200/200#.png" /><figcaption>
 captioned link (image in this case)
 </figcaption>
 </figure>
@@ -21,7 +21,7 @@ note that the whole paragraph is captioned, so a linebreak is needed for images
 </p>
 <figure>
 <p>
-<img src="http://placekitten.com/200/200#.png" alt="http://placekitten.com/200/200#.png" title="http://placekitten.com/200/200#.png" />
+<img src="https://placekitten.com/200/200#.png" alt="https://placekitten.com/200/200#.png" title="https://placekitten.com/200/200#.png" />
 see?
 </p>
 <figcaption>
diff --git a/org/testdata/captions.org b/org/testdata/captions.org
index 87b6e40..fb3f0b5 100644
--- a/org/testdata/captions.org
+++ b/org/testdata/captions.org
@@ -6,11 +6,11 @@ echo "i have a caption!"
 #+END_SRC
 
 #+CAPTION: captioned link (image in this case)
-[[http://placekitten.com/200/200#.png]]
+[[https://placekitten.com/200/200#.png]]
 
 note that the whole paragraph is captioned, so a linebreak is needed for images to caption correctly
 
 #+CAPTION: captioned link (image in this case)
-[[http://placekitten.com/200/200#.png]]
+[[https://placekitten.com/200/200#.png]]
 see?
 
diff --git a/org/testdata/inline.html b/org/testdata/inline.html
index d0b73f3..80280c7 100644
--- a/org/testdata/inline.html
+++ b/org/testdata/inline.html
@@ -91,12 +91,12 @@ regular link to a file (video) <video src="my-video.mp4" title="my-video.mp4">my
 </li>
 <li>
 <p>
-regular link to http (image) <img src="http://www.example.com/my-img.png" alt="http://www.example.com/my-img.png" title="http://www.example.com/my-img.png" />
+regular link to http (image) <img src="http://placekitten.com/200/200#.png" alt="http://placekitten.com/200/200#.png" title="http://placekitten.com/200/200#.png" />
 </p>
 </li>
 <li>
 <p>
-regular link to https (image) <img src="https://www.example.com/my-img.png" alt="https://www.example.com/my-img.png" title="https://www.example.com/my-img.png" />
+regular link to https (image) <img src="https://placekitten.com/200/200#.png" alt="https://placekitten.com/200/200#.png" title="https://placekitten.com/200/200#.png" />
 </p>
 </li>
 <li>
diff --git a/org/testdata/inline.org b/org/testdata/inline.org
index 6984d68..9a11445 100644
--- a/org/testdata/inline.org
+++ b/org/testdata/inline.org
@@ -23,6 +23,6 @@
   2. regular link [[https://example.com][example.com]] link with description
   3. regular link to a file (image) [[file:my-img.png]]
   4. regular link to a file (video) [[my-video.mp4]]
-  5. regular link to http (image) [[http://www.example.com/my-img.png]]
-  6. regular link to https (image) [[https://www.example.com/my-img.png]]
+  5. regular link to http (image) [[http://placekitten.com/200/200#.png]]
+  6. regular link to https (image) [[https://placekitten.com/200/200#.png]]
   7. auto link, i.e. not inside =\[[square brackets]\]= https://www.example.com
diff --git a/org/testdata/keywords.html b/org/testdata/keywords.html
index 5803476..32c4cad 100644
--- a/org/testdata/keywords.html
+++ b/org/testdata/keywords.html
@@ -11,7 +11,7 @@ and <span style="text-decoration: underline;">multiple</span> lines of <strong>c
 and an image with custom html attributes and a caption
 </p>
 <figure>
-<img src="http://placekitten.com/200/200#.png" alt="http://placekitten.com/200/200#.png" title="http://placekitten.com/200/200#.png" style="border: 10px solid black"/>
+<img src="https://placekitten.com/200/200#.png" alt="https://placekitten.com/200/200#.png" title="https://placekitten.com/200/200#.png" style="border: 10px solid black"/>
 <figcaption>
 kittens!
 </figcaption>
diff --git a/org/testdata/keywords.org b/org/testdata/keywords.org
index cba15b3..f6f0f6b 100644
--- a/org/testdata/keywords.org
+++ b/org/testdata/keywords.org
@@ -10,4 +10,4 @@ echo "a bash source block with custom html attributes"
 and an image with custom html attributes and a caption
 #+CAPTION: kittens!
 #+ATTR_HTML: :style "border: 10px solid black"
-[[http://placekitten.com/200/200#.png]]
+[[https://placekitten.com/200/200#.png]]