diff --git a/m4.include/fsusage.m4 b/m4.include/fsusage.m4
index 8e9e2cb5b..89637af30 100644
--- a/m4.include/fsusage.m4
+++ b/m4.include/fsusage.m4
@@ -33,7 +33,7 @@ dnl Enable large-file support. This has the effect of changing the size
 dnl of field f_blocks in 'struct statvfs' from 32 bit to 64 bit on
 dnl glibc/Hurd, HP-UX 11, Solaris (32-bit mode). It also changes the size
 dnl of field f_blocks in 'struct statfs' from 32 bit to 64 bit on
-dnl MacOS X >= 10.5 (32-bit mode).
+dnl Mac OS X >= 10.5 (32-bit mode).
 AC_REQUIRE([AC_SYS_LARGEFILE])
 
 AC_MSG_NOTICE([checking how to get file system space usage])
@@ -68,7 +68,7 @@ struct statvfs fsd;
 
 #if defined __APPLE__ && defined __MACH__
 #include <limits.h>
-/* On MacOS X >= 10.5, f_blocks in 'struct statvfs' is a 32-bit quantity;
+/* On Mac OS X >= 10.5, f_blocks in 'struct statvfs' is a 32-bit quantity;
    that commonly limits file systems to 4 TiB.  Whereas f_blocks in
    'struct statfs' is a 64-bit type, thanks to the large-file support
    that was enabled above.  In this case, don't use statvfs(); use statfs()
@@ -137,7 +137,7 @@ if test $ac_fsusage_space = no; then
 fi
 
 if test $ac_fsusage_space = no; then
-  # glibc/Linux, MacOS X, FreeBSD < 5.0, NetBSD < 3.0, OpenBSD < 4.4.
+  # glibc/Linux, Mac OS X, FreeBSD < 5.0, NetBSD < 3.0, OpenBSD < 4.4.
   # (glibc/{Hurd,kFreeBSD}, FreeBSD >= 5.0, NetBSD >= 3.0,
   # OpenBSD >= 4.4, AIX, HP-UX, OSF/1, Cygwin already handled above.)
   # (On IRIX you need to include <sys/statfs.h>, not only <sys/mount.h> and
diff --git a/src/filemanager/mountlist.c b/src/filemanager/mountlist.c
index 56aa8314e..3dd783a41 100644
--- a/src/filemanager/mountlist.c
+++ b/src/filemanager/mountlist.c
@@ -1379,7 +1379,7 @@ get_fs_usage (char const *file, char const *disk, struct fs_usage *fsp)
     fsp->fsu_blocksize = PROPAGATE_ALL_ONES (fsd.f_fsize);
 
 #elif defined STAT_STATFS2_BSIZE        /* glibc/Linux, 4.3BSD, SunOS 4, \
-                                           MacOS X < 10.4, FreeBSD < 5.0, \
+                                           Mac OS X < 10.4, FreeBSD < 5.0, \
                                            NetBSD < 3.0, OpenBSD < 4.4 */
 
     struct statfs fsd;