diff --git a/engine.cmake b/engine.cmake
index f12044a..5af28f1 100644
--- a/engine.cmake
+++ b/engine.cmake
@@ -118,6 +118,7 @@ set(ENGINE_PLATFORM_UNIX_SRC
 
 	# X11
 	source/Platform/Unix/Xlib.cpp
+	source/Platform/Unix/XRandR.cpp
 	source/Platform/Unix/X11Display.cpp
 	source/Platform/Unix/X11Input.cpp
 	source/Platform/Unix/X11Keyboard.cpp
diff --git a/source/Platform/Unix/XRandR.cpp b/source/Platform/Unix/XRandR.cpp
new file mode 100644
index 0000000..c934218
--- /dev/null
+++ b/source/Platform/Unix/XRandR.cpp
@@ -0,0 +1,34 @@
+#include "XRandR.h"
+#include <Spectre/System/Log.h>
+#include <algorithm>
+
+namespace sp {
+
+bool XRandR::FindMode(::Display* disp, unsigned int width, unsigned int height, unsigned int bpp, SizeID *id, short *rate)
+{
+	::XRRScreenSize *xrrs;
+	int num_sizes;
+
+	xrrs = XRRSizes(disp, 0, &num_sizes);
+	for(int i = 0; i < num_sizes; i++) {
+
+		Log::debug("Mode %dx%d", xrrs[i].width, xrrs[i].height);
+
+		if (xrrs[i].width != width && xrrs[i].height != height) {
+			continue;
+		}
+
+		short   *rates;
+		int     num_rates;
+
+		rates = XRRRates(disp, 0, i, &num_rates);
+		if (num_rates > 0) {
+			*id = i;
+			*rate = rates[num_rates - 1];
+			return true;
+		}
+	}
+	return false;
+}
+
+} // namespace sp
\ No newline at end of file
diff --git a/source/Platform/Unix/XRandR.h b/source/Platform/Unix/XRandR.h
new file mode 100644
index 0000000..6faac86
--- /dev/null
+++ b/source/Platform/Unix/XRandR.h
@@ -0,0 +1,18 @@
+
+#ifndef PLATFORM_UNIX_XRANDR_H
+#define PLATFORM_UNIX_XRANDR_H
+
+#include <X11/extensions/Xrandr.h>
+
+namespace sp { namespace XRandR {
+
+struct VideoMode {
+	SizeID   size;
+	short    rate;
+};
+
+bool FindMode(::Display* disp, unsigned int width, unsigned int height, unsigned int bpp, SizeID *id, short *rate);
+
+} } // sp::XRandR
+
+#endif /* PLATFORM_UNIX_XRANDR_H */