diff --git a/hw/dmx/dmxgc.c b/hw/dmx/dmxgc.c
index 234316797..ec15d27aa 100644
--- a/hw/dmx/dmxgc.c
+++ b/hw/dmx/dmxgc.c
@@ -49,7 +49,7 @@
 #include "pixmapstr.h"
 #include "migc.h"
 
-static GCFuncs dmxGCFuncs = {
+static const GCFuncs dmxGCFuncs = {
     dmxValidateGC,
     dmxChangeGC,
     dmxCopyGC,
@@ -59,7 +59,7 @@ static GCFuncs dmxGCFuncs = {
     dmxCopyClip,
 };
 
-static GCOps dmxGCOps = {
+static const GCOps dmxGCOps = {
     dmxFillSpans,
     dmxSetSpans,
     dmxPutImage,
diff --git a/hw/dmx/dmxgc.h b/hw/dmx/dmxgc.h
index c8ecb53a0..c5c6b7732 100644
--- a/hw/dmx/dmxgc.h
+++ b/hw/dmx/dmxgc.h
@@ -41,8 +41,8 @@
 
 /** GC private area. */
 typedef struct _dmxGCPriv {
-    GCOps *ops;
-    GCFuncs *funcs;
+    const GCOps *ops;
+    const GCFuncs *funcs;
     XlibGC gc;
     Bool msc;
 } dmxGCPrivRec, *dmxGCPrivPtr;