diff --git a/configure.in b/configure.in
index 2619ddc2f5c..0c8f6ed2269 100644
--- a/configure.in
+++ b/configure.in
@@ -177,7 +177,7 @@ AC_CHECK_LIB(nsl, gethostbyaddr, [
 
 AC_CHECK_LIB(crypt, crypt, [
  AC_ADD_LIBRARY(crypt)
- AC_DEFINE(HAVE_LIBCRYPT,,[ ]) ], [])
+ AC_DEFINE(HAVE_LIBCRYPT,1,[ ]) ], [])
 
 dnl The sin may be in a library which need not be specifed
 dnl as well as res_search resides in libsocket