diff --git a/basis/x11/glx/glx.factor b/basis/x11/glx/glx.factor
index dc6157b87f..b459b55f46 100644
--- a/basis/x11/glx/glx.factor
+++ b/basis/x11/glx/glx.factor
@@ -84,6 +84,14 @@ X-FUNCTION: void* glXGetProcAddress ( char* procname ) ;
 ! GLX_ARB_get_proc_address extension
 X-FUNCTION: void* glXGetProcAddressARB ( char* procname ) ;
 
+! GLX_ARB_multisample
+CONSTANT: GLX_SAMPLE_BUFFERS 100000
+CONSTANT: GLX_SAMPLES 100001
+
+! GLX_ARB_fbconfig_float
+CONSTANT: GLX_RGBA_FLOAT_TYPE HEX: 20B9
+CONSTANT: GLX_RGBA_FLOAT_BIT  HEX: 0004
+
 ! GLX Events
 ! (also skipped for now. only has GLXPbufferClobberEvent, the rest is handled by xlib methinks)