diff --git a/configure.in.in b/configure.in.in
index 8b3272b1a6a..8e1086c4cc4 100644
--- a/configure.in.in
+++ b/configure.in.in
@@ -251,7 +251,7 @@ else
 fi
 AC_MISSING_FCLOSE_DECL
 dnl QNX requires unix.h to allow functions in libunix to work properly
-AC_CHECK_HEADERS(fcntl.h unistd.h crypt.h sys/file.h memory.h pwd.h grp.h sys/socket.h sys/wait.h syslog.h string.h sys/varargs.h stdarg.h sys/time.h signal.h netinet/in.h dlfcn.h limits.h sys/types.h unix.h arpa/inet.h locale.h)
+AC_CHECK_HEADERS(fcntl.h unistd.h crypt.h sys/file.h memory.h pwd.h grp.h sys/socket.h sys/wait.h syslog.h string.h sys/varargs.h stdarg.h sys/time.h signal.h netinet/in.h dlfcn.h limits.h sys/types.h unix.h arpa/inet.h locale.h sys/select.h)
 
 dnl Checks for typedefs, structures, and compiler characteristics.
 AC_STRUCT_TM
diff --git a/ext/standard/fsock.c b/ext/standard/fsock.c
index 05401f5f344..c23ae5eef98 100644
--- a/ext/standard/fsock.c
+++ b/ext/standard/fsock.c
@@ -55,6 +55,9 @@
 #if defined(AF_UNIX)
 #include <sys/un.h>
 #endif
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
 
 #include <string.h>
 #include <errno.h>