diff --git a/vvp/configure.in b/vvp/configure.in
index d83c5b3b9..f89900b41 100644
--- a/vvp/configure.in
+++ b/vvp/configure.in
@@ -7,7 +7,8 @@ AC_CHECK_TOOL(STRIP, strip, true)
 
 AC_PROG_INSTALL
 
-AC_ARG_ENABLE(vvp-debug, "interactive debugger for VVP runtime.", AC_DEFINE(ENABLE_VVP_DEBUG))
+AC_ARG_ENABLE(vvp-debug, vvp-debug -- interactive debugger for VVP runtime.,
+	AC_DEFINE(ENABLE_VVP_DEBUG))
 
 AC_CHECK_HEADERS(getopt.h)