diff --git a/commons-serialize-xml/src/main/java/io/gitlab/jfronny/commons/serialize/xml/NativeXmlReader.java b/commons-serialize-xml/src/main/java/io/gitlab/jfronny/commons/serialize/xml/NativeXmlReader.java
index 80a3ad3..04e1d5f 100644
--- a/commons-serialize-xml/src/main/java/io/gitlab/jfronny/commons/serialize/xml/NativeXmlReader.java
+++ b/commons-serialize-xml/src/main/java/io/gitlab/jfronny/commons/serialize/xml/NativeXmlReader.java
@@ -796,17 +796,13 @@ public class NativeXmlReader implements Closeable {
         int unused = nextNonWhitespace(true);
         pos--;
 
-        if (pos + 5 > limit && !fillBuffer(5)) {
+        if (pos + 5 > limit && !fillBuffer(2)) {
             return;
         }
 
         int p = pos;
         char[] buf = buffer;
-        if (buf[p] != '<'
-                || buf[p + 1] != '?'
-                || buf[p + 2] != 'x'
-                || buf[p + 3] != 'm'
-                || buf[p + 4] != 'l') {
+        if (buf[p] != '<' || buf[p + 1] != '?') {
             return; // not a header!
         }