diff --git a/bin/caam b/bin/caam
index 3b26bf7..30380ac 100755
--- a/bin/caam
+++ b/bin/caam
@@ -1,6 +1,6 @@
 #!/bin/sh
 # caam - Configure And And Make
-# (C)2008-2018 by HIROSE, Yuuji [yuuji/at/gentei.org]
+# (C)2008-2020 by HIROSE, Yuuji [yuuji/at/gentei.org]
 # $HGid$
 # http://www.gentei.org/~yuuji/software/caam/
 
@@ -183,6 +183,7 @@
 		CONFIG_SHELL DESTDIR \
   		PKG_CONFIG PKG_CONFIG_PATH \
 		CAAM_PREFIXES CAAM_ADD CFG MAKE MKOPT \
+		ACLOCAL AUTOCONF AUTOMAKE GETOPT \
 		$acvars $otvars; do
   eval "v=\$$e"
   if [ x"$v" != x"" ]; then