diff --git a/configure.ac b/configure.ac
index f6fdb0e..6693c47 100644
--- a/configure.ac
+++ b/configure.ac
@@ -124,7 +124,7 @@ AS_CASE([$host_os],
 	[linux*|kfreebsd*-gnu|freebsd*],
 	[
 		libc_name=`ldd /usr/bin/yes | grep 'libc\.' | cut -d ' ' -f 1 | tr -d '\t'`
-		if test "${libc_name}" == ""; then
+		if test "${libc_name}" = ""; then
 			# Default libc on most system.
 			libc_name="libc.so.6"
 		fi
diff --git a/src/lib/accept.c b/src/lib/accept.c
index 80434fc..9866b62 100644
--- a/src/lib/accept.c
+++ b/src/lib/accept.c
@@ -87,7 +87,7 @@ LIBC_ACCEPT_DECL
 	return tsocks_accept(LIBC_ACCEPT_ARGS);
 }
 
-#if (defined(__linux__))
+#if (defined(__linux__) || defined(__NetBSD__))
 
 TSOCKS_LIBC_DECL(accept4, LIBC_ACCEPT4_RET_TYPE, LIBC_ACCEPT4_SIG)
 
diff --git a/src/lib/torsocks.h b/src/lib/torsocks.h
index 33da526..38eb079 100644
--- a/src/lib/torsocks.h
+++ b/src/lib/torsocks.h
@@ -242,6 +242,9 @@ struct hostent **result, int *h_errnop
 #define LIBC_SYSCALL_SIG long int number, ...
 #define LIBC_SYSCALL_ARGS number
 
+#endif /* __linux__ */
+
+#if defined(__linux__) || defined(__NetBSD__)
 /* accept4(2) */
 #define LIBC_ACCEPT4_NAME accept4
 #define LIBC_ACCEPT4_NAME_STR XSTR(LIBC_ACCEPT4_NAME)
@@ -249,8 +252,8 @@ struct hostent **result, int *h_errnop
 #define LIBC_ACCEPT4_SIG \
 	int sockfd, struct sockaddr *addr, socklen_t *addrlen, int flags
 #define LIBC_ACCEPT4_ARGS sockfd, addr, addrlen, flags
+#endif
 
-#endif /* __linux__ */
 
 #if (defined(__FreeBSD__) || defined(__darwin__) || defined(__NetBSD__))
 
@@ -414,7 +417,7 @@ TSOCKS_DECL(accept, LIBC_ACCEPT_RET_TYPE, LIBC_ACCEPT_SIG)
 		LIBC_ACCEPT_NAME(LIBC_ACCEPT_SIG)
 
 /* accept4(2) */
-#if (defined(__linux__))
+#if (defined(__linux__) || defined(__NetBSD__))
 extern TSOCKS_LIBC_DECL(accept4, LIBC_ACCEPT4_RET_TYPE, LIBC_ACCEPT4_SIG)
 TSOCKS_DECL(accept4, LIBC_ACCEPT4_RET_TYPE, LIBC_ACCEPT4_SIG)
 #define LIBC_ACCEPT4_DECL LIBC_ACCEPT4_RET_TYPE \