diff --git a/Core/Resources/Db/MySQL/db.sql b/Core/Resources/Db/MySQL/db.sql
index 51757cda..d7aa87b4 100644
--- a/Core/Resources/Db/MySQL/db.sql
+++ b/Core/Resources/Db/MySQL/db.sql
@@ -36,8 +36,8 @@ CREATE TABLE calendarobjects (
     etag VARBINARY(32),
     size INT(11) UNSIGNED NOT NULL,
     componenttype VARBINARY(8),
-    firstoccurence INT(11) UNSIGNED,
-    lastoccurence INT(11) UNSIGNED,
+    firstoccurence INT(11),
+    lastoccurence INT(11),
     uid VARBINARY(200),
     UNIQUE(calendarid, uri)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
diff --git a/Core/Resources/Db/PgSQL/db.sql b/Core/Resources/Db/PgSQL/db.sql
index 7335dbb2..e9237c49 100644
--- a/Core/Resources/Db/PgSQL/db.sql
+++ b/Core/Resources/Db/PgSQL/db.sql
@@ -37,8 +37,8 @@ CREATE TABLE calendarobjects (
     etag TEXT,
     size INT CHECK (size > 0) NOT NULL,
     componenttype TEXT,
-    firstoccurence INT CHECK (firstoccurence > 0),
-    lastoccurence INT CHECK (lastoccurence > 0),
+    firstoccurence INT,
+    lastoccurence INT,
     uid TEXT
 );