diff --git a/src/content/sanitizer/sanitizer_test.go b/src/content/sanitizer/sanitizer_test.go
index 8f49f05..53ffb3d 100644
--- a/src/content/sanitizer/sanitizer_test.go
+++ b/src/content/sanitizer/sanitizer_test.go
@@ -8,10 +8,11 @@ import "testing"
 
 func TestValidInput(t *testing.T) {
 	input := `<p>This is a <strong>text</strong> with an image: <img src="http://example.org/" alt="Test" loading="lazy">.</p>`
-	output := Sanitize("http://example.org/", input)
+	want := `<p>This is a <strong>text</strong> with an image: <img src="http://example.org/" alt="Test" loading="lazy" referrerpolicy="no-referrer">.</p>`
+	have := Sanitize("http://example.org/", input)
 
-	if input != output {
-		t.Errorf(`Wrong output: "%s" != "%s"`, input, output)
+	if have != want {
+		t.Errorf("Wrong output: \nwant: %#v\nhave: %#v", want, have)
 	}
 }
 
@@ -27,31 +28,31 @@ func TestImgWithTextDataURL(t *testing.T) {
 
 func TestImgWithDataURL(t *testing.T) {
 	input := `<img src="data:image/gif;base64,test" alt="Example">`
-	expected := `<img src="data:image/gif;base64,test" alt="Example" loading="lazy">`
-	output := Sanitize("http://example.org/", input)
+	want := `<img src="data:image/gif;base64,test" alt="Example" loading="lazy" referrerpolicy="no-referrer">`
+	have := Sanitize("http://example.org/", input)
 
-	if output != expected {
-		t.Errorf(`Wrong output: %s`, output)
+	if have != want {
+		t.Errorf("Wrong output:\nwant: %s\nhave: %s", want, have)
 	}
 }
 
 func TestImgWithSrcset(t *testing.T) {
 	input := `<img srcset="example-320w.jpg, example-480w.jpg 1.5x,   example-640w.jpg 2x, example-640w.jpg 640w" src="example-640w.jpg" alt="Example">`
-	expected := `<img srcset="http://example.org/example-320w.jpg, http://example.org/example-480w.jpg 1.5x, http://example.org/example-640w.jpg 2x, http://example.org/example-640w.jpg 640w" src="http://example.org/example-640w.jpg" alt="Example" loading="lazy">`
-	output := Sanitize("http://example.org/", input)
+	want := `<img srcset="http://example.org/example-320w.jpg, http://example.org/example-480w.jpg 1.5x, http://example.org/example-640w.jpg 2x, http://example.org/example-640w.jpg 640w" src="http://example.org/example-640w.jpg" alt="Example" loading="lazy" referrerpolicy="no-referrer">`
+	have := Sanitize("http://example.org/", input)
 
-	if output != expected {
-		t.Errorf(`Wrong output: %s`, output)
+	if have != want {
+		t.Errorf("Wrong output:\nwant: %s\nhave: %s", want, have)
 	}
 }
 
 func TestImgWithSrcsetAndDataURL(t *testing.T) {
 	input := `<img srcset="data:image/gif;base64,test" src="http://example.org/example-320w.jpg" alt="Example">`
-	expected := `<img srcset="data:image/gif;base64,test" src="http://example.org/example-320w.jpg" alt="Example" loading="lazy">`
-	output := Sanitize("http://example.org/", input)
+	want := `<img srcset="data:image/gif;base64,test" src="http://example.org/example-320w.jpg" alt="Example" loading="lazy" referrerpolicy="no-referrer">`
+	have := Sanitize("http://example.org/", input)
 
-	if output != expected {
-		t.Errorf(`Wrong output: %s`, output)
+	if have != want {
+		t.Errorf("Wrong output:\nwant: %s\nhave: %s", want, have)
 	}
 }
 
@@ -67,16 +68,16 @@ func TestSourceWithSrcsetAndMedia(t *testing.T) {
 
 func TestMediumImgWithSrcset(t *testing.T) {
 	input := `<img alt="Image for post" class="t u v ef aj" src="https://miro.medium.com/max/5460/1*aJ9JibWDqO81qMfNtqgqrw.jpeg" srcset="https://miro.medium.com/max/552/1*aJ9JibWDqO81qMfNtqgqrw.jpeg 276w, https://miro.medium.com/max/1000/1*aJ9JibWDqO81qMfNtqgqrw.jpeg 500w" sizes="500px" width="2730" height="3407">`
-	expected := `<img alt="Image for post" src="https://miro.medium.com/max/5460/1*aJ9JibWDqO81qMfNtqgqrw.jpeg" srcset="https://miro.medium.com/max/552/1*aJ9JibWDqO81qMfNtqgqrw.jpeg 276w, https://miro.medium.com/max/1000/1*aJ9JibWDqO81qMfNtqgqrw.jpeg 500w" sizes="500px" loading="lazy">`
-	output := Sanitize("http://example.org/", input)
+	want := `<img alt="Image for post" src="https://miro.medium.com/max/5460/1*aJ9JibWDqO81qMfNtqgqrw.jpeg" srcset="https://miro.medium.com/max/552/1*aJ9JibWDqO81qMfNtqgqrw.jpeg 276w, https://miro.medium.com/max/1000/1*aJ9JibWDqO81qMfNtqgqrw.jpeg 500w" sizes="500px" loading="lazy" referrerpolicy="no-referrer">`
+	have := Sanitize("http://example.org/", input)
 
-	if output != expected {
-		t.Errorf(`Wrong output: %s`, output)
+	if have != want {
+		t.Errorf("Wrong output:\nwant: %s\nhave: %s", want, have)
 	}
 }
 
 func TestSelfClosingTags(t *testing.T) {
-	input := `<p>This <br> is a <strong>text</strong> <br/>with an image: <img src="http://example.org/" alt="Test" loading="lazy"/>.</p>`
+	input := `<p>This <br> is a <strong>text</strong><br/>.</p>`
 	output := Sanitize("http://example.org/", input)
 
 	if input != output {
@@ -95,11 +96,11 @@ func TestTable(t *testing.T) {
 
 func TestRelativeURL(t *testing.T) {
 	input := `This <a href="/test.html">link is relative</a> and this image: <img src="../folder/image.png"/>`
-	expected := `This <a href="http://example.org/test.html" rel="noopener noreferrer" target="_blank" referrerpolicy="no-referrer">link is relative</a> and this image: <img src="http://example.org/folder/image.png" loading="lazy"/>`
-	output := Sanitize("http://example.org/", input)
+	want := `This <a href="http://example.org/test.html" rel="noopener noreferrer" target="_blank" referrerpolicy="no-referrer">link is relative</a> and this image: <img src="http://example.org/folder/image.png" loading="lazy" referrerpolicy="no-referrer"/>`
+	have := Sanitize("http://example.org/", input)
 
-	if expected != output {
-		t.Errorf(`Wrong output: "%s" != "%s"`, expected, output)
+	if want != have {
+		t.Errorf("Wrong output:\nwant: %s\nhave: %s", want, have)
 	}
 }
 
@@ -165,11 +166,11 @@ func TestInvalidNestedTag(t *testing.T) {
 
 func TestValidIFrame(t *testing.T) {
 	input := `<iframe src="http://example.org/"></iframe>`
-	expected := `<iframe src="http://example.org/" sandbox="allow-scripts allow-same-origin allow-popups" loading="lazy"></iframe>`
-	output := Sanitize("http://example.org/", input)
+	want := `<iframe src="http://example.org/" sandbox="allow-scripts allow-same-origin allow-popups" loading="lazy"></iframe>`
+	have := Sanitize("http://example.org/", input)
 
-	if expected != output {
-		t.Errorf("Wrong output:\nwant: %s\nhave: %s", expected, output)
+	if want != have {
+		t.Errorf("Wrong output:\nwant: %s\nhave: %s", want, have)
 	}
 }