diff --git a/src/spell.c b/src/spell.c
index d866a2d..24abce4 100644
--- a/src/spell.c
+++ b/src/spell.c
@@ -3996,9 +3996,10 @@
 		    n = arridx[depth] + curi[depth];
 		    ++curi[depth];
 		    c = byts[n];
-		    if (c == 0)
+		    if (c == 0 || depth >= MAXWLEN - 1)
 		    {
-			// End of word, deal with the word.
+			// End of word or reached maximum length, deal with the
+			// word.
 			// Don't use keep-case words in the fold-case tree,
 			// they will appear in the keep-case tree.
 			// Only use the word when the region matches.