diff --git a/c++tools/configure b/c++tools/configure
index 3f511b2dbee..a288f7abe5d 100755
--- a/c++tools/configure
+++ b/c++tools/configure
@@ -2978,9 +2978,9 @@ else
 fi
 
 case "$enable_maintainer_mode" in
-  ("yes") maintainer_mode=yes ;;
-  ("no") maintainer=no ;;
-  (*) as_fn_error $? "unknown maintainer mode $enable_maintainer_mode" "$LINENO" 5 ;;
+  yes) maintainer_mode=yes ;;
+  no) maintainer_mode=no ;;
+  *) as_fn_error $? "unknown maintainer mode $enable_maintainer_mode" "$LINENO" 5 ;;
 esac
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking maintainer-mode" >&5
 $as_echo_n "checking maintainer-mode... " >&6; }
diff --git a/c++tools/configure.ac b/c++tools/configure.ac
index 1b08f7575b6..70fcb641db9 100644
--- a/c++tools/configure.ac
+++ b/c++tools/configure.ac
@@ -58,9 +58,9 @@ AS_HELP_STRING([--enable-maintainer-mode],
 [enable maintainer mode.  Add rules to rebuild configurey bits]),,
 [enable_maintainer_mode=no])
 case "$enable_maintainer_mode" in
-  ("yes") maintainer_mode=yes ;;
-  ("no") maintainer=no ;;
-  (*) AC_MSG_ERROR([unknown maintainer mode $enable_maintainer_mode]) ;;
+  yes) maintainer_mode=yes ;;
+  no) maintainer_mode=no ;;
+  *) AC_MSG_ERROR([unknown maintainer mode $enable_maintainer_mode]) ;;
 esac
 AC_MSG_CHECKING([maintainer-mode])
 AC_MSG_RESULT([$maintainer_mode])