diff --git a/librttopo_geos.patch b/librttopo_geos.patch
new file mode 100644
index 0000000..0e25d59
--- /dev/null
+++ b/librttopo_geos.patch
@@ -0,0 +1,55 @@
+diff -rupN librttopo/configure.ac librttopo-new/configure.ac
+--- librttopo/configure.ac	2019-07-27 08:55:02.000000000 +0200
++++ librttopo-new/configure.ac	2021-02-27 10:13:26.397946908 +0100
+@@ -84,36 +84,10 @@ AC_CONFIG_FILES([Makefile \
+ 		headers/librttopo_geom.h \
+ 		rttopo.pc])
+ 
+-#-----------------------------------------------------------------------
+-#   --with-geosconfig
+-#
+-AC_ARG_WITH([geosconfig],
+-    [AS_HELP_STRING([--with-geosconfig=FILE], [specify an alternative geos-config file])],
+-	[GEOSCONFIG="$withval"], [GEOSCONFIG=""])
+-if test "x$GEOSCONFIG" = "x"; then
+-    # GEOSCONFIG was not specified, so search within the current path
+-    AC_PATH_PROG([GEOSCONFIG], [geos-config])
+-    # If we couldn't find geos-config, display an error
+-    if test "x$GEOSCONFIG" = "x"; then
+-            AC_MSG_ERROR([could not find geos-config within the current path. You may need to try re-running configure with a --with-geosconfig parameter.])
+-    fi
+-else
+-    # GEOSCONFIG was specified; display a message to the user
+-    if test "x$GEOSCONFIG" = "xyes"; then
+-            AC_MSG_ERROR([you must specify a parameter to --with-geosconfig, e.g. --with-geosconfig=/path/to/geos-config])
+-    else
+-            if test -f $GEOSCONFIG; then
+-                    AC_MSG_RESULT([Using user-specified geos-config file: $GEOSCONFIG])
+-            else
+-                    AC_MSG_ERROR([the user-specified geos-config file $GEOSCONFIG does not exist])
+-            fi
+-    fi
+-fi
+-# Extract the linker and include flags
+-GEOS_LDFLAGS=`$GEOSCONFIG --ldflags`
+-GEOS_CFLAGS=-I`$GEOSCONFIG --includes`
+-AC_SUBST([GEOS_LDFLAGS])
+-AC_SUBST([GEOS_CFLAGS])
++PKG_CHECK_MODULES([GEOS], [geos], , AC_MSG_ERROR(['geos' is required but it doesn't seem to be installed on this system.]))
++GEOS_LDFLAGS="$GEOS_LIBS"
++AC_SUBST(GEOS_CFLAGS)
++AC_SUBST(GEOS_LDFLAGS)
+ # Ensure that we can parse geos_c.h
+ CPPFLAGS_SAVE="$CPPFLAGS"
+ CPPFLAGS="$GEOS_CFLAGS"
+@@ -125,8 +99,8 @@ LIBS="$GEOS_LDFLAGS"
+ AC_SEARCH_LIBS(GEOSContext_setErrorMessageHandler_r,geos_c,,AC_MSG_ERROR([could not find libgeos_c (or obsolete 'libgeos_c' < v.3.5.0 found) - you may need to specify the directory of a geos-config file using --with-geosconfig]))
+ LIBS="$LIBS_SAVE"
+ LIBS="$LIBS $GEOS_LDFLAGS -lgeos_c"
+-GEOS_MAJOR_VERSION=`$GEOSCONFIG --version | cut -d. -f1 | sed 's/[[^0-9]]//g'`
+-GEOS_MINOR_VERSION=`$GEOSCONFIG --version | cut -d. -f2 | sed 's/[[^0-9]]//g'`
++GEOS_MAJOR_VERSION=`${PKGCONFIG:-pkg-config} --modversion geos | cut -d. -f1 | sed 's/[[^0-9]]//g'`
++GEOS_MINOR_VERSION=`${PKGCONFIG:-pkg-config} --modversion geos | cut -d. -f2 | sed 's/[[^0-9]]//g'`
+ RTGEOM_GEOS_VERSION="$GEOS_MAJOR_VERSION$GEOS_MINOR_VERSION"
+ AC_DEFINE_UNQUOTED([RTGEOM_GEOS_VERSION], [$RTGEOM_GEOS_VERSION], [GEOS library version])
+ AC_SUBST([RTGEOM_GEOS_VERSION])