diff -ur gdal-3.8.0.orig/gcore/gdaljp2metadatagenerator.cpp gdal-3.8.0/gcore/gdaljp2metadatagenerator.cpp
--- gdal-3.8.0.orig/gcore/gdaljp2metadatagenerator.cpp	2023-11-18 10:50:42.858058910 -0500
+++ gdal-3.8.0/gcore/gdaljp2metadatagenerator.cpp	2023-11-18 10:52:52.805490659 -0500
@@ -357,7 +357,12 @@
 /************************************************************************/
 
 static void GDALGMLJP2XPathErrorHandler(void * /* userData */,
-                                        xmlErrorPtr error)
+#if LIBXML_VERSION >= 21200
+                                        const xmlError *error
+#else
+                                        xmlErrorPtr error
+#endif
+)
 {
     if (error->domain == XML_FROM_XPATH && error->str1 != nullptr &&
         error->int1 < static_cast<int>(strlen(error->str1)))
diff -ur gdal-3.8.0.orig/port/cpl_xml_validate.cpp gdal-3.8.0/port/cpl_xml_validate.cpp
--- gdal-3.8.0.orig/port/cpl_xml_validate.cpp	2023-11-18 13:23:43.173950425 -0500
+++ gdal-3.8.0/port/cpl_xml_validate.cpp	2023-11-18 13:26:22.462050184 -0500
@@ -914,7 +914,7 @@
 
     if (strstr(pszStr, "since this namespace was already imported") == nullptr)
     {
-        xmlErrorPtr pErrorPtr = xmlGetLastError();
+        const xmlError *pErrorPtr = xmlGetLastError();
         const char *pszFilename = static_cast<char *>(ctx);
         char *pszStrDup = CPLStrdup(pszStr);
         int nLen = static_cast<int>(strlen(pszStrDup));