diff --git a/sc2/build/unix/build.config b/sc2/build/unix/build.config
index 39cacdec4..623229d0b 100644
--- a/sc2/build/unix/build.config
+++ b/sc2/build/unix/build.config
@@ -35,7 +35,9 @@ uqm_requirements()
 	have_library vorbisfile || exit 1
 
 
-	# Add defines for HAVE_SETENV, HAVE_STRUPR and HAVE_STRICMP
+	# Add defines for HAVE_READDIR_R, HAVE_SETENV, HAVE_STRUPR
+	# and HAVE_STRICMP
+	define_have_symbol readdir_r
 	define_have_symbol setenv
 	define_have_symbol strupr
 	define_have_symbol stricmp
diff --git a/sc2/build/unix/config_proginfo b/sc2/build/unix/config_proginfo
index b5d2719be..879ba4596 100644
--- a/sc2/build/unix/config_proginfo
+++ b/sc2/build/unix/config_proginfo
@@ -260,6 +260,9 @@ LIB_zlib_DEPEND_DETECT_BIN="pkgconfig"
 # Describe the symbols (possibly) used:                                      #
 ##############################################################################
 
+SYMBOL_readdir_r_EXTRA="#include <dirent.h>
+"
+
 SYMBOL_wchar_t_EXTRA="#include <stddef.h>
 "
 
diff --git a/sc2/src/config_unix.h.in b/sc2/src/config_unix.h.in
index 1aa9b7ad9..03dbf92ea 100644
--- a/sc2/src/config_unix.h.in
+++ b/sc2/src/config_unix.h.in
@@ -26,6 +26,9 @@
 /* Defined if words are stored with the most significant byte first */
 @WORDS_BIGENDIAN@
 
+/* Defined if your system has readdir_r of its own */
+@HAVE_READDIR_R@
+
 /* Defined if your system has setenv of its own */
 @HAVE_SETENV@
 
diff --git a/sc2/src/msvc++/config.h b/sc2/src/msvc++/config.h
index 200482cac..dd4271f93 100644
--- a/sc2/src/msvc++/config.h
+++ b/sc2/src/msvc++/config.h
@@ -27,6 +27,9 @@
 /* Define if words are stored with the most significant byte first */
 #undef WORDS_BIGENDIAN
 
+/* Defined if your system has readdir_r of its own */
+#undef HAVE_READDIR_R
+
 /* Defined if your system has setenv of its own */
 #undef HAVE_SETENV