diff --git a/docs/changelog/7.x.x.txt b/docs/changelog/7.x.x.txt
index c3f8f856a..2cb57844d 100644
--- a/docs/changelog/7.x.x.txt
+++ b/docs/changelog/7.x.x.txt
@@ -2,6 +2,7 @@
  - Fixed a bug where empty version tags were not deleted. (Martin Kamerbeek / Oqapi)
  - fixed: deploying a package doesn't commit version tag with autocommit on
  - fixed rfe #76: group delete causes problems
+ - fixed #10526: icalInterval in Calendar.pm
 
 7.7.10
  - Made a change to LDAP auth that adds an OR to that query so that it also searches for a row with fieldData REGEXP '^uid=(value-from-ldap-directory-server),'. (Wes Morgan)
diff --git a/docs/upgrades/upgrade_7.7.10-7.7.11.pl b/docs/upgrades/upgrade_7.7.10-7.7.11.pl
index f93e75904..a224cf331 100644
--- a/docs/upgrades/upgrade_7.7.10-7.7.11.pl
+++ b/docs/upgrades/upgrade_7.7.10-7.7.11.pl
@@ -31,6 +31,7 @@ my $quiet; # this line required
 my $session = start(); # this line required
 
 # upgrade functions go here
+setDefaultIcalInterval($session);
 
 finish($session); # this line required
 
@@ -44,6 +45,16 @@ finish($session); # this line required
 #    print "DONE!\n" unless $quiet;
 #}
 
+#----------------------------------------------------------------------------
+# Describe what our function does
+sub setDefaultIcalInterval {
+    my $session = shift;
+    print "\tSet default ICAL interval in older calendars... " unless $quiet;
+    $session->db->write("UPDATE Calendar SET icalInterval = 7776000 where icalInterval is null or icalInterval = ''");
+    # and here's our code
+    print "DONE!\n" unless $quiet;
+}
+
 
 # -------------- DO NOT EDIT BELOW THIS LINE --------------------------------