diff --git a/app/code/core/Mage/Backend/etc/system.xsd b/app/code/core/Mage/Backend/etc/system.xsd
index cd794a2851aa3..93127e66ce750 100644
--- a/app/code/core/Mage/Backend/etc/system.xsd
+++ b/app/code/core/Mage/Backend/etc/system.xsd
@@ -410,7 +410,7 @@
             </xs:documentation>
         </xs:annotation>
         <xs:restriction base="xs:string">
-            <xs:pattern value="[A-Z]+[a-z0-9]{1,}(_[A-Z][A-Z0-9a-z]+){1,}(::[A-Z0-9a-z_]+)?" />
+            <xs:pattern value="[A-Z]+[A-Za-z0-9]{1,}(_[A-Z][A-Z0-9a-z]+){1,}(::[A-Z0-9a-z_]+)?" />
             <xs:minLength value="5" />
         </xs:restriction>
     </xs:simpleType>
diff --git a/app/code/core/Mage/Backend/etc/system_file.xsd b/app/code/core/Mage/Backend/etc/system_file.xsd
index 84111c1b7200f..4eb147af034f3 100644
--- a/app/code/core/Mage/Backend/etc/system_file.xsd
+++ b/app/code/core/Mage/Backend/etc/system_file.xsd
@@ -412,7 +412,7 @@
             </xs:documentation>
         </xs:annotation>
         <xs:restriction base="xs:string">
-            <xs:pattern value="[A-Z]+[a-z0-9]{1,}(_[A-Z][A-Z0-9a-z]+){1,}(::[A-Z0-9a-z_]+)?" />
+            <xs:pattern value="[A-Z]+[A-Za-z0-9]{1,}(_[A-Z][A-Z0-9a-z]+){1,}(::[A-Z0-9a-z_]+)?" />
             <xs:minLength value="5" />
         </xs:restriction>
     </xs:simpleType>