--- ImageMagick-7.1.0-4/configure.ac	2021-07-18 16:47:31.000000000 +0100
+++ ImageMagick-7.1.0-4.mod/configure.ac	2021-08-17 11:52:56.748517700 +0100
@@ -2389,46 +2389,23 @@
 if test "$with_jxl" != 'yes'; then
     DISTCHECK_CONFIG_FLAGS="${DISTCHECK_CONFIG_FLAGS} --with-jxl=$with_jxl "
 fi
-if test "$enable_static" = 'yes'; then
-    if test "$with_utilities" = 'yes'; then
-        with_jxl='no'
-    fi
-fi
 
-# Check for the JPEG-XL library.
 have_jxl='no'
+JXL_CFLAGS=''
 JXL_LIBS=''
+JXL_PKG=''
 if test "$with_jxl" != 'no'; then
   AC_MSG_RESULT([-------------------------------------------------------------])
-  AC_MSG_CHECKING([for jpeg-xl])
+  PKG_CHECK_MODULES([JXL],[libjxl >= 0.5, libjxl_threads >= 0.5],[have_jxl=yes],[have_jxl=no])
   AC_MSG_RESULT([])
-  failed=0
-  passed=0
-  AC_CHECK_HEADER([jxl/decode.h],[passed=`expr $passed + 1`],[failed=`expr $failed + 1`])
-  AC_CHECK_HEADER([jxl/encode.h],[passed=`expr $passed + 1`],[failed=`expr $failed + 1`])
-  # This check should be changed once we have a .pc file for the JPEG-XL library.
-  if test "$enable_static" != 'yes'; then
-    AC_CHECK_LIB([jxl],[JxlDecoderCreate],[passed=`expr $passed + 1`],[failed=`expr $failed + 1`],[])
-    AC_CHECK_LIB([jxl],[JxlEncoderSetBasicInfo],[passed=`expr $passed + 1`],[failed=`expr $failed + 1`],[])
-  fi
-
-  AC_MSG_CHECKING([if jpeg-xl package is complete])
-  if test $passed -gt 0; then
-      if test $failed -gt 0; then
-          AC_MSG_RESULT([no -- some components failed test])
-          have_jxl='no (failed tests)'
-      else
-          JXL_LIBS='-ljxl -ljxl_threads'
+fi
+if test "$have_jxl" = 'yes'; then
+          CFLAGS="$JXL_CFLAGS $CFLAGS"
           LIBS="$JXL_LIBS $LIBS"
           AC_DEFINE([JXL_DELEGATE],[1],[Define if you have jpeg-xl library])
-          AC_MSG_RESULT([yes])
-          have_jxl='yes'
-      fi
-  else
-      AC_MSG_RESULT([no])
-  fi
 fi
 AM_CONDITIONAL([JXL_DELEGATE],[test "$have_jxl" = 'yes'])
+AC_SUBST([JXL_CFLAGS])
 AC_SUBST([JXL_LIBS])
 
 dnl ===========================================================================