diff --git a/chrome/content/zotero/xpcom/prefs.js b/chrome/content/zotero/xpcom/prefs.js
index bb1cf5d4f1..189d450da4 100644
--- a/chrome/content/zotero/xpcom/prefs.js
+++ b/chrome/content/zotero/xpcom/prefs.js
@@ -49,7 +49,7 @@ Zotero.Prefs = new function(){
 		if (!fromVersion) {
 			fromVersion = 0;
 		}
-		var toVersion = 6;
+		var toVersion = 7;
 		if (fromVersion < toVersion) {
 			for (var i = fromVersion + 1; i <= toVersion; i++) {
 				switch (i) {
@@ -103,6 +103,12 @@ Zotero.Prefs = new function(){
 							this.clear('export.noteQuickCopy.setting');
 						}
 						break;
+					
+					// Re-enable hardware acceleration in Zotero 7 for all the people who turned it
+					// off to fix PDF rendering problems
+					case 7:
+						this.clear('layers.acceleration.disabled', true);
+						break;
 				}
 			}
 			this.set('prefVersion', toVersion);