diff --git a/auto/lib/libxslt/conf b/auto/lib/libxslt/conf
index 877c171..30ef6d0 100644
--- a/auto/lib/libxslt/conf
+++ b/auto/lib/libxslt/conf
@@ -73,6 +73,18 @@
 
 
 if [ $ngx_found = yes ]; then
+
     CORE_INCS="$CORE_INCS $ngx_feature_path"
     CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
+
+else
+
+cat << END
+
+$0: error: the HTTP XSLT module requires the libxml2/libxslt
+libraries. You can either do not enable the module or install the libraries.
+
+END
+
+    exit 1
 fi