diff --git a/resources/schema.xsd b/resources/schema.xsd
index fb7d3a1..215affd 100644
--- a/resources/schema.xsd
+++ b/resources/schema.xsd
@@ -1,34 +1,62 @@
 <xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
+  <xs:simpleType name="dec_hex_num">
+  	<xs:restriction base="xs:string">
+  		<xs:pattern value="([0-9]+|0x[0-9a-fA-F]+)"></xs:pattern>
+  	</xs:restriction>
+  </xs:simpleType>
+  <xs:simpleType name="elfclass_type">
+  	<xs:union>
+  		<xs:simpleType>
+        		<xs:restriction base="xs:integer">
+				<xs:minInclusive value="32"/>
+           			<xs:maxInclusive value="32"/>
+			</xs:restriction>
+        	</xs:simpleType>
+        	<xs:simpleType>
+        		<xs:restriction base="xs:integer">
+				<xs:minInclusive value="64"/>
+           			<xs:maxInclusive value="64"/>
+			</xs:restriction>
+        	</xs:simpleType>
+        	<xs:simpleType>
+        		<!-- This is in case something unsupported is encountered -->
+        		<xs:restriction base="xs:integer">
+				<xs:minInclusive value="-1"/>
+           			<xs:maxInclusive value="-1"/>
+			</xs:restriction>
+        	</xs:simpleType>
+  	</xs:union>
+  </xs:simpleType>
   <xs:element name="patchelfcrc">
     <xs:complexType>
       <xs:sequence>
         <xs:element name="settings">
           <xs:complexType>
             <xs:sequence>
-              <xs:element type="xs:string" name="poly"/>
-              <xs:element type="xs:string" name="start"/>
-              <xs:element type="xs:string" name="rev"/>
-              <xs:element type="xs:string" name="xor"/>
-              <xs:element type="xs:integer" name="elfclass"/>
+              <xs:element type="dec_hex_num" name="poly"/>
+              <xs:element type="dec_hex_num" name="start"/>
+              <xs:element type="xs:string" fixed="" name="rev" minOccurs="0" maxOccurs="1"/>
+              <xs:element type="dec_hex_num" name="xor"/>
+              <xs:element type="elfclass_type" name="elfclass"/>
             </xs:sequence>
           </xs:complexType>
         </xs:element>
         <xs:element name="sections">
           <xs:complexType>
-            <xs:sequence>
+            <xs:choice minOccurs="1" maxOccurs="unbounded">
               <xs:element name="crc">
                 <xs:complexType>
                   <xs:simpleContent>
-                    <xs:extension base="xs:string">
+                    <xs:extension base="dec_hex_num">
                       <xs:attribute type="xs:string" name="name"/>
-                      <xs:attribute type="xs:integer" name="index"/>
-                      <xs:attribute type="xs:string" name="vma"/>
-                      <xs:attribute type="xs:string" name="size"/>
+                      <xs:attribute type="dec_hex_num" name="index"/>
+                      <xs:attribute type="dec_hex_num" name="vma"/>
+                      <xs:attribute type="dec_hex_num" name="size"/>
                     </xs:extension>
                   </xs:simpleContent>
                 </xs:complexType>
               </xs:element>
-            </xs:sequence>
+            </xs:choice>
           </xs:complexType>
         </xs:element>
       </xs:sequence>
diff --git a/src/xml.c b/src/xml.c
index 56c8ff2..fe08e6d 100644
--- a/src/xml.c
+++ b/src/xml.c
@@ -40,8 +40,8 @@ int xml_write_crcs_to_file(const char *path, const uint32_t *crcs, SlList *secti
 		goto ret_none;
 	}
 
-	//xmlTextWriterSetIndentString(writer, BAD_CAST "\t");
-	//xmlTextWriterSetIndent(writer, 1);
+	xmlTextWriterSetIndentString(writer, BAD_CAST "\t");
+	xmlTextWriterSetIndent(writer, 1);
 
 	xmlTextWriterStartDocument(writer, NULL, "UTF-8", NULL);
 	/* Generate the root node */
@@ -51,7 +51,10 @@ int xml_write_crcs_to_file(const char *path, const uint32_t *crcs, SlList *secti
 	xmlTextWriterStartElement(writer, BAD_CAST "settings");
 	xmlTextWriterWriteFormatElement(writer, BAD_CAST "poly", "0x%" PRIx64, crc_params->polynomial);
 	xmlTextWriterWriteFormatElement(writer, BAD_CAST "start", "0x%" PRIx32, crc_params->start_value);
-	xmlTextWriterWriteFormatElement(writer, BAD_CAST "rev", "%s", crc_params->rev ? "true" : "false");
+	if (crc_params->rev) {
+		xmlTextWriterStartElement(writer, BAD_CAST "rev");
+		xmlTextWriterEndElement(writer);
+	}
 	xmlTextWriterWriteFormatElement(writer, BAD_CAST "xor", "0x%" PRIx32, crc_params->xor);
 	bitsize = elf_patch_get_bits(ep);
 	if (bitsize < 0) {