diff --git a/_cache_service_worker.js b/_cache_service_worker.js
index 52004c1..c52dc42 100644
--- a/_cache_service_worker.js
+++ b/_cache_service_worker.js
@@ -14,7 +14,7 @@
 */
 
 var PRECACHE_ID='rom-patcher-js';
-var PRECACHE_VERSION='v28b';
+var PRECACHE_VERSION='v281';
 var PRECACHE_URLS=[
 	'/RomPatcher.js/','/RomPatcher.js/index.html',
 	'/RomPatcher.js/manifest.json',
diff --git a/index.html b/index.html
index 535e1e2..27be2a9 100644
--- a/index.html
+++ b/index.html
@@ -180,7 +180,7 @@
 		<button id="button-settings" class="button-outer"><img src="style/icon_settings.svg" class="icon settings" /> <span data-localize="settings">Settings</span></button>
 	</div>
 
-	Rom Patcher JS <small>v2.8</small> by <a href="/">Marc Robledo</a>
+	Rom Patcher JS <small>v2.8.1</small> by <a href="/">Marc Robledo</a>
 	<br />
 	<img src="style/icon_github.svg" class="icon github" /> <a href="https://github.com/marcrobledo/RomPatcher.js/" target="_blank">See on GitHub</a>
 	<img src="style/icon_heart.svg" class="icon heart" /> <a href="https://www.paypal.me/marcrobledo/5" target="_blank" rel="nofollow">Donate</a>
diff --git a/js/RomPatcher.js b/js/RomPatcher.js
index 66652a0..f174c74 100644
--- a/js/RomPatcher.js
+++ b/js/RomPatcher.js
@@ -1,4 +1,4 @@
-/* Rom Patcher JS v20230331 - Marc Robledo 2016-2023 - http://www.marcrobledo.com/license */
+/* Rom Patcher JS v20230406 - Marc Robledo 2016-2023 - http://www.marcrobledo.com/license */
 
 const TOO_BIG_ROM_SIZE=67108863;
 const HEADERS_INFO=[
@@ -141,7 +141,7 @@ function fetchPatch(customPatchIndex, compressedFileIndex){
 				patchFile=CUSTOM_PATCHER[customPatchIndex].fetchedFile=new MarcFile(arrayBuffer);
 				patchFile.fileName=customPatch.file.replace(/^.*[\/\\]/g,'');
 
-				if(patchFile.getExtension()==='zip' && patchFile.readString(4).startsWith(ZIP_MAGIC))
+				if(patchFile.getExtension()!=='jar' && patchFile.readString(4).startsWith(ZIP_MAGIC))
 					ZIPManager.parseFile(CUSTOM_PATCHER[customPatchIndex].fetchedFile, compressedFileIndex);
 				else
 					parseCustomPatch(CUSTOM_PATCHER[customPatchIndex]);
@@ -161,7 +161,7 @@ function fetchPatch(customPatchIndex, compressedFileIndex){
 				patchFile=CUSTOM_PATCHER[customPatchIndex].fetchedFile=new MarcFile(xhr.response);
 				patchFile.fileName=customPatch.file.replace(/^.*[\/\\]/g,'');
 
-				if(patchFile.getExtension()==='zip' && patchFile.readString(4).startsWith(ZIP_MAGIC))
+				if(patchFile.getExtension()!=='jar' && patchFile.readString(4).startsWith(ZIP_MAGIC))
 					ZIPManager.parseFile(CUSTOM_PATCHER[customPatchIndex].fetchedFile, compressedFileIndex);
 				else
 					parseCustomPatch(CUSTOM_PATCHER[customPatchIndex]);
@@ -184,7 +184,7 @@ function _parseROM(){
 	el('checkbox-addheader').checked=false;
 	el('checkbox-removeheader').checked=false;
 
-	if(romFile.getExtension()==='zip' && romFile.readString(4).startsWith(ZIP_MAGIC)){
+	if(romFile.getExtension()!=='jar' && romFile.readString(4).startsWith(ZIP_MAGIC)){
 		ZIPManager.parseFile(romFile);
 		setTabApplyEnabled(false);
 	}else{
@@ -653,7 +653,7 @@ function _readPatchFile(){
 	patchFile.littleEndian=false;
 
 	var header=patchFile.readString(6);
-	if(patchFile.getExtension()==='zip' && header.startsWith(ZIP_MAGIC)){
+	if(patchFile.getExtension()!=='jar' && header.startsWith(ZIP_MAGIC)){
 		patch=false;
 		validateSource();
 		setTabApplyEnabled(false);