diff --git a/src/pretix/base/templates/pretixbase/email/base.html b/src/pretix/base/templates/pretixbase/email/base.html
index b7e24cbe4..b0e13c768 100644
--- a/src/pretix/base/templates/pretixbase/email/base.html
+++ b/src/pretix/base/templates/pretixbase/email/base.html
@@ -199,7 +199,7 @@
         <tr>
             <td style="line-height: 0">
                 <img class="wide" src="data:image/png;base64,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"
-                style="max-height: 60px;">
+                style="max-height: 60px;" alt="">
             </td>
         </tr>
         <!--<![endif]-->
@@ -233,7 +233,7 @@
             <td style="line-height: 0">
                 <br>
                 <img class="wide" src="data:image/png;base64,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"
-                style="max-height: 60px;">
+                style="max-height: 60px;" alt="">
             </td>
         </tr>
         <!--<![endif]-->
diff --git a/src/pretix/base/templates/pretixbase/email/separator.html b/src/pretix/base/templates/pretixbase/email/separator.html
index 0d2e44288..f0ff2f726 100644
--- a/src/pretix/base/templates/pretixbase/email/separator.html
+++ b/src/pretix/base/templates/pretixbase/email/separator.html
@@ -3,7 +3,7 @@
     <td>
         <div style="line-height: 18px;height: 18px;">&nbsp;</div>
         <img class="wide" src="data:image/png;base64,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"
-            style="max-height: 4px;">
+            style="max-height: 4px;" alt="">
         <div style="line-height: 18px;height: 18px;">&nbsp;</div>
     </td>
 </tr>