diff --git a/NEWS b/NEWS
index 496a4c6b4..74e4bc6d2 100644
--- a/NEWS
+++ b/NEWS
@@ -8,6 +8,7 @@ Bug fixes
  - sogo-tool manage-acl not working on v2 (#4292)
  - [web] restored mail threads state of inbox on initial page load
  - [web] fixed and improved messages list in threads mode
+ - [web] sanitize value of draft auto save timer, defaults to 5 minutes
 
 2.3.23 (2017-10-18)
 -------------------
diff --git a/SoObjects/SOGo/SOGoUserDefaults.m b/SoObjects/SOGo/SOGoUserDefaults.m
index c1784aec9..a0a7828cb 100644
--- a/SoObjects/SOGo/SOGoUserDefaults.m
+++ b/SoObjects/SOGo/SOGoUserDefaults.m
@@ -372,7 +372,7 @@ NSString *SOGoWeekStartFirstFullWeek = @"FirstFullWeek";
       userLanguage = [source objectForKey: @"SOGoLanguage"];
       if (!(userLanguage && [userLanguage isKindOfClass: [NSString class]]))
         userLanguage = [(SOGoDomainDefaults *) parentSource language];
-  
+
       supportedLanguages = [[SOGoSystemDefaults sharedSystemDefaults]
                              supportedLanguages];
 
@@ -541,7 +541,14 @@ NSString *SOGoWeekStartFirstFullWeek = @"FirstFullWeek";
 
 - (void) setMailAutoSave: (NSString *) newValue
 {
-  [self setObject: newValue forKey: @"SOGoMailAutoSave"];
+  NSString *s;
+
+  if ([newValue intValue] == 0)
+    s = @"5";
+  else
+    s = newValue;
+
+  [self setObject: s forKey: @"SOGoMailAutoSave"];
 }
 
 - (NSString *) mailAutoSave
@@ -552,7 +559,7 @@ NSString *SOGoWeekStartFirstFullWeek = @"FirstFullWeek";
 
   if ([s intValue] == 0)
     s = @"5";
-  
+
   return s;
 }
 
diff --git a/UI/WebServerResources/UIxMailEditor.js b/UI/WebServerResources/UIxMailEditor.js
index 35bd436cf..ca350275e 100644
--- a/UI/WebServerResources/UIxMailEditor.js
+++ b/UI/WebServerResources/UIxMailEditor.js
@@ -384,7 +384,7 @@ function initAddresses() {
 }
 
 function initAutoSaveTimer() {
-    var autoSave = UserDefaults["SOGoMailAutoSave"];
+    var autoSave = parseInt(UserDefaults["SOGoMailAutoSave"]) || 5;
 
     if (autoSave) {
         var interval;