diff --git a/plugins/dynamix/UserAdd.page b/plugins/dynamix/UserAdd.page
index ad332da49..e7fd8955e 100644
--- a/plugins/dynamix/UserAdd.page
+++ b/plugins/dynamix/UserAdd.page
@@ -113,7 +113,7 @@ $(function(){
     url:'/webGui/include/FileUpload.php',
     data:{path:path,"csrf_token":"<?=$var['csrf_token']?>"},
     beforeEach:function(file) {
-      if (!file.type.match(/^image\/.*/)) {
+      if (!file.type.match(/^image\/png/)) {
         swal({title:"Warning",text:"Only PNG images are allowed!",type:"warning",html:true,confirmButtonText:"_(Ok)_"});
         return false;
       }
@@ -169,7 +169,7 @@ _(Description)_:
 :user_add_description_help:
 
 _(Custom image)_:
-: <span id="dropbox"><?=$void?></span><em>_(Drag-n-drop a PNG file or click the image at the left)_</em><input type="file" id="drop" accept="image/*" style="display:none">
+: <span id="dropbox"><?=$void?></span><em>_(Drag-n-drop a PNG file or click the image at the left)_</em><input type="file" id="drop" accept="image/png" style="display:none">
 
 :user_add_custom_image_help:
 
diff --git a/plugins/dynamix/UserEdit.page b/plugins/dynamix/UserEdit.page
index ea9a7385f..fa42725fa 100644
--- a/plugins/dynamix/UserEdit.page
+++ b/plugins/dynamix/UserEdit.page
@@ -119,7 +119,7 @@ $(function(){
     url:'/webGui/include/FileUpload.php',
     data:{"csrf_token":"<?=$var['csrf_token']?>"},
     beforeEach:function(file) {
-      if (!file.type.match(/^image\/.*/)) {
+      if (!file.type.match(/^image\/png/)) {
         swal({title:"Warning",text:"_(Only PNG images are allowed)_!",type:"warning",html:true,confirmButtonText:"_(Ok)_"});
         return false;
       }
@@ -180,7 +180,7 @@ _(Custom image)_:
 <?else:?>
   <?=$void?>
 <?endif;?>
-  </span><em>_(Drag-n-drop a PNG file or click the image at the left)_</em><input type="file" id="drop" accept="image/*" style="display:none">
+  </span><em>_(Drag-n-drop a PNG file or click the image at the left)_</em><input type="file" id="drop" accept="image/png" style="display:none">
 
 :user_edit_custom_image_help:
 
diff --git a/plugins/dynamix/include/SelectCase.php b/plugins/dynamix/include/SelectCase.php
index 79185f433..230a33e1e 100644
--- a/plugins/dynamix/include/SelectCase.php
+++ b/plugins/dynamix/include/SelectCase.php
@@ -79,6 +79,10 @@ div.case-name{margin-top:8px;font-family:clear-sans!important}
 <script src="<?autov('/webGui/javascript/dynamix.js')?>"></script>
 <script>
 function importFile(file) {
+  if (file.name.split(".").pop().toLowerCase() !== "png") {
+    alert("<?=_("Only png images are allowed!")?>");
+    return;
+  }  
   var reader = new FileReader();
   reader.readAsDataURL(file);
   reader.onload = function(e){$.post('/webGui/include/SelectCase.php',{mode:'file',file:'<?=$file?>',data:e.target.result,csrf_token:'<?=$_GET['csrf']?>'},function(){top.Shadowbox.close();})};