--- a/xpcom/MoreFiles/MoreFilesX.c
+++ b/xpcom/MoreFiles/MoreFilesX.c
@@ -2311,21 +2311,22 @@ FSGetVolMountInfo(
 PBGetVolMountInfo:
 BadParameter:
 
 	return ( result );
 }
 
 /*****************************************************************************/
 
-// This function exists in Mac OS X 10.5, we cannot re-define it here.
-// We don't use this function, so just don't compile it.
-#if 0
+/* Renamed from FSVolumeMount to MFX_FSVolumeMount to avoid a conflict with
+ * the FSVolumeMount function present in the system library since Mac OS X
+ * 10.5. */
+
 OSErr
-FSVolumeMount(
+MFX_FSVolumeMount(
 	const void *volMountInfo,
 	FSVolumeRefNum *volRefNum)
 {
 	OSErr			result;
 	ParamBlockRec	pb;
 
 	/* check parameters */
 	require_action(NULL != volRefNum, BadParameter, result = paramErr);
@@ -2337,17 +2338,16 @@ FSVolumeMount(
 	/* return the volume reference number */
 	*volRefNum = pb.ioParam.ioVRefNum;
 
 PBVolumeMount:
 BadParameter:
 
 	return ( result );
 }
-#endif
 
 /*****************************************************************************/
 
 OSErr
 FSMapID(
 	FSVolumeRefNum volRefNum,
 	SInt32 ugID,
 	SInt16 objType,

--- a/xpcom/MoreFiles/MoreFilesX.h
+++ b/xpcom/MoreFiles/MoreFilesX.h
@@ -1484,25 +1484,24 @@ FSGetVolMountInfo(
 	__________
 
 	Also see:	FSGetVolMountInfoSize, VolumeMount
 */
 
 /*****************************************************************************/
 
 #pragma mark FSVolumeMount
+/* Renamed from FSVolumeMount to MFX_FSVolumeMount to avoid a conflict with
+ * the FSVolumeMount function present in the system library since Mac OS X
+ * 10.5. */
 
-// This function exists in Mac OS X 10.5, we cannot re-define it here.
-// We don't use this function, so just don't compile it.
-#if 0
 OSErr
-FSVolumeMount(
+MFX_FSVolumeMount(
 	const void *volMountInfo,
 	FSVolumeRefNum *volRefNum);
-#endif
 
 /*
 	The VolumeMount function mounts a volume using a volume mounting
 	information record.
 
 	volMountInfo		--> A volume mounting information record.
 	volRefNum			<-- The volume reference number.