diff --git a/config.xsd b/config.xsd
index 7487017..d8adb11 100644
--- a/config.xsd
+++ b/config.xsd
@@ -22,7 +22,7 @@
     <!-- available PWM frequencies -->
     <xs:simpleType name="FrequencyType">
         <xs:restriction base="xs:integer">
-            <xs:minInclusive value="0"/>
+            <xs:minInclusive value="1"/>
             <xs:maxInclusive value="1000"/>
         </xs:restriction>
     </xs:simpleType>