diff --git a/code/sys/sys_local.h b/code/sys/sys_local.h
index a0d6dc24..ce9f99b3 100644
--- a/code/sys/sys_local.h
+++ b/code/sys/sys_local.h
@@ -50,6 +50,9 @@ unsigned int CON_LogSize( void );
 unsigned int CON_LogWrite( const char *in );
 unsigned int CON_LogRead( char *out, unsigned int outSize );
 
+char *Sys_BinaryPath( void );
+char *Sys_BinaryPathRelative( const char *relative );
+
 #ifdef __APPLE__
 char *Sys_StripAppBundle( char *pwd );
 #endif
diff --git a/code/sys/sys_main.c b/code/sys/sys_main.c
index 44fb0981..6101fded 100644
--- a/code/sys/sys_main.c
+++ b/code/sys/sys_main.c
@@ -721,7 +721,9 @@ char *Sys_ParseProtocolUri( const char *uri )
 #endif
 
 #ifndef DEFAULT_BASEDIR
-#	ifdef __APPLE__
+#	if defined(DEFAULT_RELATIVE_BASEDIR)
+#		define DEFAULT_BASEDIR Sys_BinaryPathRelative(DEFAULT_RELATIVE_BASEDIR)
+#	elif defined(__APPLE__)
 #		define DEFAULT_BASEDIR Sys_StripAppBundle(Sys_BinaryPath())
 #	else
 #		define DEFAULT_BASEDIR Sys_BinaryPath()
diff --git a/code/sys/sys_unix.c b/code/sys/sys_unix.c
index 07de6500..53593600 100644
--- a/code/sys/sys_unix.c
+++ b/code/sys/sys_unix.c
@@ -29,6 +29,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include <sys/stat.h>
 #include <errno.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <dirent.h>
 #include <unistd.h>
 #include <sys/mman.h>
@@ -352,6 +353,24 @@ char *Sys_Cwd( void )
 	return cwd;
 }
 
+/*
+==================
+Sys_BinaryPathRelative
+==================
+*/
+char *Sys_BinaryPathRelative(const char *relative)
+{
+	static char resolved[MAX_OSPATH];
+	char combined[MAX_OSPATH];
+
+	snprintf(combined, sizeof(combined), "%s/%s", Sys_BinaryPath(), relative);
+
+	if (!realpath(combined, resolved))
+		return NULL;
+
+	return resolved;
+}
+
 /*
 ==============================================================
 
diff --git a/code/sys/sys_win32.c b/code/sys/sys_win32.c
index e740bcd6..d67c0716 100644
--- a/code/sys/sys_win32.c
+++ b/code/sys/sys_win32.c
@@ -424,6 +424,25 @@ char *Sys_Cwd( void ) {
 	return cwd;
 }
 
+/*
+==============
+Sys_BinaryPathRelative
+==============
+*/
+char *Sys_BinaryPathRelative(const char *relative)
+{
+	static char resolved[MAX_OSPATH];
+	char combined[MAX_OSPATH];
+
+	snprintf(combined, sizeof(combined), "%s\\%s", Sys_BinaryPath(), relative);
+
+	DWORD len = GetFullPathNameA(combined, MAX_OSPATH, resolved, NULL);
+	if (len == 0 || len >= MAX_OSPATH)
+		return NULL;
+
+	return resolved;
+}
+
 /*
 ==============================================================