diff --git a/hw/xfree86/common/xf86Init.c b/hw/xfree86/common/xf86Init.c
index d098e13fd8..c0775d1637 100644
--- a/hw/xfree86/common/xf86Init.c
+++ b/hw/xfree86/common/xf86Init.c
@@ -740,7 +740,7 @@ InitOutput(ScreenInfo *pScreenInfo, int argc, char **argv)
       }
       *VT = xf86Info.vtno;
     
-      VTAtom = MakeAtom(VT_ATOM_NAME, sizeof(VT_ATOM_NAME), TRUE);
+      VTAtom = MakeAtom(VT_ATOM_NAME, sizeof(VT_ATOM_NAME) - 1, TRUE);
 
       for (i = 0, ret = Success; i < xf86NumScreens && ret == Success; i++) {
 	ret = xf86RegisterRootWindowProperty(xf86Screens[i]->scrnIndex,
diff --git a/hw/xfree86/ddc/ddcProperty.c b/hw/xfree86/ddc/ddcProperty.c
index 6ff0726d96..67351d3dc4 100644
--- a/hw/xfree86/ddc/ddcProperty.c
+++ b/hw/xfree86/ddc/ddcProperty.c
@@ -87,7 +87,7 @@ addRootWindowProperties(ScrnInfoPtr pScrn, xf86MonPtr DDC)
 	if ((EDID1rawdata = xalloc(128*sizeof(CARD8)))==NULL)
 	    return;
 
-	EDID1Atom = MakeAtom(EDID1_ATOM_NAME, sizeof(EDID1_ATOM_NAME), TRUE);
+	EDID1Atom = MakeAtom(EDID1_ATOM_NAME, sizeof(EDID1_ATOM_NAME) - 1, TRUE);
 	memcpy(EDID1rawdata, DDC->rawData, 128);
 	xf86RegisterRootWindowProperty(scrnIndex, EDID1Atom, XA_INTEGER, 8,
 		128, (unsigned char *)EDID1rawdata);
@@ -98,7 +98,7 @@ addRootWindowProperties(ScrnInfoPtr pScrn, xf86MonPtr DDC)
 	    return;
 
 	memcpy(EDID2rawdata, DDC->rawData, 256);
-	EDID2Atom = MakeAtom(EDID2_ATOM_NAME, sizeof(EDID2_ATOM_NAME), TRUE);
+	EDID2Atom = MakeAtom(EDID2_ATOM_NAME, sizeof(EDID2_ATOM_NAME) - 1, TRUE);
 	xf86RegisterRootWindowProperty(scrnIndex, EDID2Atom, XA_INTEGER, 8,
 		256, (unsigned char *)EDID2rawdata);
     }
diff --git a/hw/xfree86/modes/xf86Crtc.c b/hw/xfree86/modes/xf86Crtc.c
index 722b62be45..ecdf620480 100644
--- a/hw/xfree86/modes/xf86Crtc.c
+++ b/hw/xfree86/modes/xf86Crtc.c
@@ -2031,7 +2031,7 @@ xf86DisableUnusedFunctions(ScrnInfoPtr pScrn)
 static void
 xf86OutputSetEDIDProperty (xf86OutputPtr output, void *data, int data_len)
 {
-    Atom edid_atom = MakeAtom(EDID_ATOM_NAME, sizeof(EDID_ATOM_NAME), TRUE);
+    Atom edid_atom = MakeAtom(EDID_ATOM_NAME, sizeof(EDID_ATOM_NAME) - 1, TRUE);
 
     /* This may get called before the RandR resources have been created */
     if (output->randr_output == NULL)