https://sourceforge.net/p/xmlrpc-c/code/3151
https://bugs.gentoo.org/870253
--- a/common.mk
+++ b/common.mk
@@ -281,7 +281,7 @@
         -L$(BLDDIR)/lib/expat/xmlparse -lxmlrpc_xmlparse \
         -L$(BLDDIR)/lib/expat/xmltok   -lxmlrpc_xmltok
 else
-  LDLIBS_XML = $(shell xml2-config --libs)
+  LDLIBS_XML = $(shell ${PKG_CONFIG} libxml-2.0 --libs)
 endif
 
 # LIBXMLRPC_UTIL_LIBDEP is the string of linker options you need on the link
--- a/configure.in
+++ b/configure.in
@@ -742,6 +742,36 @@
 
 
 dnl =======================================================================
+dnl Finding Libxml2
+dnl =======================================================================
+
+AC_MSG_CHECKING(for Libxml2 library)
+
+if ${PKG_CONFIG} libxml-2.0; then
+  HAVE_LIBXML2=yes
+else
+  HAVE_LIBXML2=no
+fi
+
+AC_MSG_RESULT($HAVE_LIBXML2)
+
+AC_ARG_ENABLE(libxml2-backend,
+  [  --enable-libxml2-backend  Use libxml2 instead of built-in expat], ,
+enable_libxml2_backend=no)
+AC_MSG_CHECKING(whether to build the libxml2 backend)
+AC_MSG_RESULT($enable_libxml2_backend)
+
+if test $enable_libxml2_backend = yes; then
+  if test $HAVE_LIBXML2 = no; then
+    AC_MSG_ERROR([You specified --enable-libxml2_backend, but don't appear to have libxml2 installed (no pkg-config file for it in your pkg-config search path), so we cannot not build for libxml2])
+  fi
+fi
+
+ENABLE_LIBXML2_BACKEND=$enable_libxml2_backend
+AC_SUBST(ENABLE_LIBXML2_BACKEND)
+
+
+dnl =======================================================================
 dnl Checks for build options.
 dnl =======================================================================
 
@@ -763,22 +793,6 @@
 fi
 AC_SUBST(HAVE_LIBWWW_SSL_DEFINE)
 
-dnl Check to see if we should build the libxml2 backend.
-AC_ARG_ENABLE(libxml2-backend,
-  [  --enable-libxml2-backend  Use libxml2 instead of built-in expat], ,
-enable_libxml2_backend=no)
-AC_MSG_CHECKING(whether to build the libxml2 backend)
-AC_MSG_RESULT($enable_libxml2_backend)
-
-if test $enable_libxml2_backend = yes; then
-  AC_CHECK_PROG(have_xml2_config, xml2-config, yes, no)
-  if test $have_xml2_config = no; then
-    AC_MSG_ERROR([You specified --enable-libxml2_backend, but don't appear to have libxml2 installed (no working xml2-config in your command search path), so we cannot not build for libxml2])
-  fi
-fi
-ENABLE_LIBXML2_BACKEND=$enable_libxml2_backend
-AC_SUBST(ENABLE_LIBXML2_BACKEND)
-
 dnl =======================================================================
 dnl Compiler information
 dnl =======================================================================
--- a/src/Makefile
+++ b/src/Makefile
@@ -68,7 +68,7 @@
 
 ifeq ($(ENABLE_LIBXML2_BACKEND),yes)
   XMLRPC_XML_PARSER = xmlrpc_libxml2
-  XML_PARSER_LIBDEP = $(shell xml2-config --libs)
+  XML_PARSER_LIBDEP = $(shell ${PKG_CONFIG} libxml-2.0 --libs)
   XML_PARSER_LIBDEP_DEP =
   XML_PKGCONFIG_REQ = libxml-2.0
 else
@@ -276,7 +276,7 @@
   -Isrcdir/lib/util/include \
 
 ifeq ($(ENABLE_LIBXML2_BACKEND),yes)
-  LIBXML_INCLUDES = $(shell xml2-config --cflags)
+  LIBXML_INCLUDES = $(shell ${PKG_CONFIG} libxml-2.0 --cflags)
 else
   LIBXML_INCLUDES = -Isrcdir/lib/expat/xmlparse
 endif
--- a/src/cpp/Makefile
+++ b/src/cpp/Makefile
@@ -46,7 +46,7 @@
 endif
 
 ifeq ($(ENABLE_LIBXML2_BACKEND),yes)
-  XML_PARSER_LIBDEP = $(shell xml2-config --libs)
+  XML_PARSER_LIBDEP = $(shell ${PKG_CONFIG} libxml-2.0 --libs)
 else
   XML_PARSER_LIBDEP = \
     -L$(BLDDIR)/lib/expat/xmlparse -lxmlrpc_xmlparse \