diff --git a/src/cmd/du.C b/src/cmd/du.c
similarity index 100%
rename from src/cmd/du.C
rename to src/cmd/du.c
diff --git a/src/cmd/ls.C b/src/cmd/ls.c
similarity index 100%
rename from src/cmd/ls.C
rename to src/cmd/ls.c
diff --git a/src/cmd/md5sum.C b/src/cmd/md5sum.c
similarity index 100%
rename from src/cmd/md5sum.C
rename to src/cmd/md5sum.c
diff --git a/src/cmd/mkdir.C b/src/cmd/mkdir.c
similarity index 100%
rename from src/cmd/mkdir.C
rename to src/cmd/mkdir.c