diff --git a/configure.ac b/configure.ac
index cde95ed09..57a60647a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -397,6 +397,10 @@ fi
 if test "x$enable_dap" = xyes; then
    AC_DEFINE([USE_DAP], [1], [if true, build DAP Client])
    AC_DEFINE([ENABLE_DAP], [1], [if true, build DAP Client])
+#AC_CHECK_HEADER(sys/socket.h, ,AC_DEFINE([NO_SYS_SOCKET_H], [], [no sys/socket.h]))
+#AC_CHECK_HEADER(socket.h, ,AC_DEFINE([NO_SOCKET_H], [], [no socket.h]))
+AC_CHECK_HEADERS([sys/socket.h socket.h])
+AC_CHECK_TYPES([socklen_t])
 fi
 
 if test "x$enable_dap_remote_tests" = xyes; then
diff --git a/libdap2/nccommon.h b/libdap2/nccommon.h
index 9ffeec498..6ef8f24c8 100644
--- a/libdap2/nccommon.h
+++ b/libdap2/nccommon.h
@@ -19,7 +19,6 @@
 #define nullfree(m) {if((m)!=NULL) {free(m);} else {}}
 #endif
 
-
 /* Misc. code controls */
 #define FILLCONSTRAINT TRUE
 
diff --git a/libdap2/ncdap.h b/libdap2/ncdap.h
index b3ca46071..1a316e5c5 100644
--- a/libdap2/ncdap.h
+++ b/libdap2/ncdap.h
@@ -15,6 +15,16 @@
 #include <string.h>
 #include <stdio.h>
 
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#elif defined HAVE_SOCKET_H
+#include <socket.h>
+#endif
+
+#ifndef HAVE_SOCKLEN_T
+typedef int socklen_t;
+#endif
+
 #include "ncbytes.h"
 #include "nclist.h"
 #include "nchashmap.h"