Index: b/m4/gpg-error.m4
===================================================================
--- b/m4/gpg-error.m4
+++ b/m4/gpg-error.m4
@@ -15,19 +15,25 @@
 dnl
 AC_DEFUN([AM_PATH_GPG_ERROR],
 [ AC_REQUIRE([AC_CANONICAL_HOST])
+
+  gpg_error_config_prefix=""
+  dnl Accept --with-gpg-error-prefix and make it work the same as
+  dnl --with-libgpg-error-prefix below, for backwards compatibility,
+  dnl but do not document this old, inconsistently-named option.
+  AC_ARG_WITH(gpg-error-prefix,,
+     gpg_error_config_prefix="$withval",)
+
   dnl --with-libgpg-error-prefix=PFX is the preferred name for this option,
   dnl since that is consistent with how our three siblings use the directory/
   dnl package name in --with-$dir_name-prefix=PFX.
+  dnl If both --with-gpg-error-prefix and --with-libgpg-error-prefix
+  dnl are given, the preferred name overrides the backwards
+  dnl compatibility option.
   AC_ARG_WITH(libgpg-error-prefix,
             AC_HELP_STRING([--with-libgpg-error-prefix=PFX],
                            [prefix where GPG Error is installed (optional)]),
-     gpg_error_config_prefix="$withval", gpg_error_config_prefix="")
+     gpg_error_config_prefix="$withval",)
 
-  dnl Accept --with-gpg-error-prefix and make it work the same as
-  dnl --with-libgpg-error-prefix above, for backwards compatibility,
-  dnl but do not document this old, inconsistently-named option.
-  AC_ARG_WITH(gpg-error-prefix,,
-     gpg_error_config_prefix="$withval", gpg_error_config_prefix="")
 
   if test x$gpg_error_config_prefix != x ; then
      if test x${GPG_ERROR_CONFIG+set} != xset ; then