diff --git a/src/spellfile.c b/src/spellfile.c
index 5962a10..7620aff 100644
--- a/src/spellfile.c
+++ b/src/spellfile.c
@@ -5585,10 +5585,12 @@
 
     /*
      * Go through the whole case-folded tree, soundfold each word and put it
-     * in the trie.
+     * in the trie.  Bail out if the tree is empty.
      */
     byts = slang->sl_fbyts;
     idxs = slang->sl_fidxs;
+    if (byts == NULL || idxs == NULL)
+	return FAIL;
 
     arridx[0] = 0;
     curi[0] = 1;