diff --git a/js/twister_formatpost.js b/js/twister_formatpost.js
index 4f85430..76db014 100644
--- a/js/twister_formatpost.js
+++ b/js/twister_formatpost.js
@@ -902,7 +902,7 @@ function setPostImagePreview(elem, links) {
             for (var i = 0; i < links.length; i++) {
                 if (/^[^?]+\.(?:jpe?g|gif|png|webp)$/i.test(links[i].href)) {
                     var url = proxyURL(links[i].href);
-                    previewContainer.append($('<img src="' + url + '" class="image-preview" width="100%" />'));
+                    previewContainer.append($('<img src="' + url + '" class="image-preview" />'));
                 }
             }
         }
diff --git a/theme_nin/css/style.css b/theme_nin/css/style.css
index 33cd2d9..e6a269e 100644
--- a/theme_nin/css/style.css
+++ b/theme_nin/css/style.css
@@ -1065,6 +1065,10 @@ samp {
   background: black;
 }
 
+.preview-container img {
+  width: 100%;
+}
+
 .post-stats {
   display: flex;
   height: 34px;
diff --git a/theme_nin/sass/_postboard.sass b/theme_nin/sass/_postboard.sass
index ac9bebb..a67b64c 100755
--- a/theme_nin/sass/_postboard.sass
+++ b/theme_nin/sass/_postboard.sass
@@ -274,6 +274,8 @@
     text-align: center
     overflow-y: auto
     background: black
+    img
+        width: 100%
 
 .post-stats
     display: flex
diff --git a/theme_nin_night/css/style.css b/theme_nin_night/css/style.css
index b59d449..8d7dc0b 100644
--- a/theme_nin_night/css/style.css
+++ b/theme_nin_night/css/style.css
@@ -1080,6 +1080,10 @@ samp {
   font-size: small;
 }
 
+.preview-container img {
+  width: 100%;
+}
+
 .post-stats {
   display: flex;
   height: 34px;