--- a/packages/nlp/CMakeLists.txt
+++ b/packages/nlp/CMakeLists.txt
@@ -2,7 +2,8 @@ cmake_minimum_required(VERSION 3.5)
 project(swipl-nlp)
 
 include("../cmake/PrologPackage.cmake")
-add_subdirectory(libstemmer_c)
+AC_CHECK_HEADERS(libstemmer.h)
+if(HAVE_LIBSTEMMER_H)
 
 AC_CHECK_FUNCS(wcsdup)
 
@@ -27,7 +28,7 @@ swipl_plugin(
 swipl_plugin(
     snowball
     C_SOURCES snowball.c
-    THREADED C_LIBS libstemmer
+    THREADED C_LIBS stemmer
     PL_LIBS snowball.pl)
 
 add_custom_target(nlp)
@@ -37,4 +38,5 @@ pkg_doc(nlp
 	SECTION
 	    snowball.pl isub.pl)
 
+endif(HAVE_LIBSTEMMER_H)
 test_libs(nlp)
--- a/packages/nlp/snowball.c
+++ b/packages/nlp/snowball.c
@@ -35,7 +35,7 @@
 #include <config.h>
 #include <SWI-Prolog.h>
 #include <SWI-Stream.h>
-#include "libstemmer_c/include/libstemmer.h"
+#include <libstemmer.h>
 #include <pthread.h>
 #include <string.h>
 #include <assert.h>