diff --git a/src/main/resources/concrete-cif-1.0.xsd b/src/main/resources/concrete-cif-1.0.xsd
index 2de0e85..ddd4978 100644
--- a/src/main/resources/concrete-cif-1.0.xsd
+++ b/src/main/resources/concrete-cif-1.0.xsd
@@ -334,6 +334,15 @@
                     <xs:simpleContent>
                         <xs:extension base="xs:string">
                             <xs:attribute name="name" type="string-required" use="required" />
+                            <xs:attribute name="storage" use="optional">
+                                <xs:simpleType>
+                                    <xs:restriction base="xs:string">
+                                        <xs:enumeration value="file" />
+                                        <xs:enumeration value="database" />
+                                    </xs:restriction>
+                                </xs:simpleType>
+                            </xs:attribute>
+                            <xs:attribute name="overwrite" type="xs:boolean" use="optional" />
                             <xs:attribute name="package" type="handle" use="required" />
                         </xs:extension>
                     </xs:simpleContent>
diff --git a/src/test/resources/cifs-bad/config-1.xml b/src/test/resources/cifs-bad/config-1.xml
new file mode 100644
index 0000000..7d02a49
--- /dev/null
+++ b/src/test/resources/cifs-bad/config-1.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0"?>
+<concrete5-cif version="1.0">
+    <config>
+        <option />
+    </config>
+</concrete5-cif>
diff --git a/src/test/resources/cifs-bad/config-2.xml b/src/test/resources/cifs-bad/config-2.xml
new file mode 100644
index 0000000..4e106d5
--- /dev/null
+++ b/src/test/resources/cifs-bad/config-2.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0"?>
+<concrete5-cif version="1.0">
+    <config>
+        <option name="" package="" />
+    </config>
+</concrete5-cif>
diff --git a/src/test/resources/cifs-bad/config-3.xml b/src/test/resources/cifs-bad/config-3.xml
new file mode 100644
index 0000000..e9006b3
--- /dev/null
+++ b/src/test/resources/cifs-bad/config-3.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0"?>
+<concrete5-cif version="1.0">
+    <config>
+        <option name="o1" storage="" package="my_package">foo</option>
+    </config>
+</concrete5-cif>
diff --git a/src/test/resources/cifs-bad/config-4.xml b/src/test/resources/cifs-bad/config-4.xml
new file mode 100644
index 0000000..a976ed4
--- /dev/null
+++ b/src/test/resources/cifs-bad/config-4.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0"?>
+<concrete5-cif version="1.0">
+    <config>
+        <option name="o1" storage="wrong" package="my_package">foo</option>
+    </config>
+</concrete5-cif>
diff --git a/src/test/resources/cifs-bad/config-5.xml b/src/test/resources/cifs-bad/config-5.xml
new file mode 100644
index 0000000..6ec2b3e
--- /dev/null
+++ b/src/test/resources/cifs-bad/config-5.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0"?>
+<concrete5-cif version="1.0">
+    <config>
+        <option name="o1" overwrite="" package="my_package">foo</option>
+    </config>
+</concrete5-cif>
diff --git a/src/test/resources/cifs-bad/config-6.xml b/src/test/resources/cifs-bad/config-6.xml
new file mode 100644
index 0000000..606a5ae
--- /dev/null
+++ b/src/test/resources/cifs-bad/config-6.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0"?>
+<concrete5-cif version="1.0">
+    <config>
+        <option name="o1" overwrite="wrong" package="my_package">foo</option>
+    </config>
+</concrete5-cif>
diff --git a/src/test/resources/cifs-good/config.xml b/src/test/resources/cifs-good/config.xml
new file mode 100644
index 0000000..dc795cf
--- /dev/null
+++ b/src/test/resources/cifs-good/config.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0"?>
+<concrete5-cif version="1.0">
+    <config>
+        <option name="o1" package="" />
+        <option name="o2" package="my_package" />
+        <option name="o3" storage="file" package="" />
+        <option name="o4" storage="file" package="my_package" />
+        <option name="o5" storage="database" package="" />
+        <option name="o6" storage="database" package="my_package" />
+        <option name="o7" package="">foo</option>
+        <option name="o8" package="my_package">foo</option>
+        <option name="o9" storage="file" package="">foo</option>
+        <option name="o10" storage="file" package="my_package">foo</option>
+        <option name="o11" storage="database" package="">foo</option>
+        <option name="o12" storage="database" package="my_package">foo</option>
+        <option name="o13" storage="database" overwrite="false" package="my_package">foo</option>
+        <option name="o14" storage="database" overwrite="true" package="my_package">foo</option>
+    </config>
+</concrete5-cif>