diff --git a/configure.ac b/configure.ac
index 1beb4b1951c3b0a06c479de5d20805a95b509721..1f09964db495810c573790d4a00ba5a819625a07 100644
--- a/configure.ac
+++ b/configure.ac
@@ -231,7 +231,8 @@ if test "x$enable_assembler" = xyes ; then
     found=no
     for tmp_f in aes-encrypt-internal.asm aes-decrypt-internal.asm \
 		 arcfour-crypt.asm camellia-crypt-internal.asm \
-		 md5-compress.asm memxor.asm serpent-encrypt.asm \
+		 md5-compress.asm memxor.asm \
+		 serpent-encrypt.asm serpent-decrypt.asm \
 		 sha1-compress.asm machine.m4; do
 #       echo "Looking for $srcdir/$asm_path/$tmp_f"
       if test -f "$srcdir/$asm_path/$tmp_f"; then