diff --git a/apps/ls.cpp b/apps/ls.cpp
index 1b8d73d6..c654ad08 100644
--- a/apps/ls.cpp
+++ b/apps/ls.cpp
@@ -4,6 +4,7 @@
 #include <os/Directory.h>
 #include <os/File.h>
 #include <os/FileSystem.h>
+#include <os/Mode.h>
 #include <pwd.h>
 
 void find_user_and_group(struct stat& st, StringView& owner, StringView& group)
@@ -92,15 +93,18 @@ Result<int> luna_main(int argc, char** argv)
 
             find_user_and_group(st, owner, group);
 
+            char formatted_mode[11];
+            os::format_mode(st.st_mode, formatted_mode);
+
             if (!human_readable && !si)
             {
-                os::println("%6o %u %4s %4s %10lu %s%s%s", st.st_mode, st.st_nlink, owner.chars(), group.chars(),
+                os::println("%s %u %4s %4s %10lu %s%s%s", formatted_mode, st.st_nlink, owner.chars(), group.chars(),
                             st.st_size, file.chars(), link.is_empty() ? "" : " -> ", link.chars());
             }
             else
             {
                 auto size = TRY(to_dynamic_unit(st.st_size, 10, false, si ? Unit::SI : Unit::Binary, false));
-                os::println("%6o %u %4s %4s %6s %s%s%s", st.st_mode, st.st_nlink, owner.chars(), group.chars(),
+                os::println("%s %u %4s %4s %6s %s%s%s", formatted_mode, st.st_nlink, owner.chars(), group.chars(),
                             size.chars(), file.chars(), link.is_empty() ? "" : " -> ", link.chars());
             }
         }
diff --git a/libos/CMakeLists.txt b/libos/CMakeLists.txt
index b4872abe..3ce41249 100644
--- a/libos/CMakeLists.txt
+++ b/libos/CMakeLists.txt
@@ -11,6 +11,7 @@ set(SOURCES
     src/Directory.cpp
     src/Main.cpp
     src/Path.cpp
+    src/Mode.cpp
 )
 
 add_library(os ${SOURCES})
diff --git a/libos/include/os/Mode.h b/libos/include/os/Mode.h
new file mode 100644
index 00000000..98263e28
--- /dev/null
+++ b/libos/include/os/Mode.h
@@ -0,0 +1,8 @@
+#pragma once
+
+#include <sys/types.h>
+
+namespace os
+{
+    void format_mode(mode_t mode, char out[11]);
+}
diff --git a/libos/src/Mode.cpp b/libos/src/Mode.cpp
new file mode 100644
index 00000000..7fc87d06
--- /dev/null
+++ b/libos/src/Mode.cpp
@@ -0,0 +1,33 @@
+#include <os/Mode.h>
+#include <sys/stat.h>
+
+namespace os
+{
+    static char filetype(mode_t mode)
+    {
+        if (S_ISREG(mode)) return '-';
+        if (S_ISDIR(mode)) return 'd';
+
+        if (S_ISCHR(mode)) return 'c';
+        if (S_ISLNK(mode)) return 'l';
+        if (S_ISFIFO(mode)) return 'p';
+
+        return '?';
+    }
+
+    void format_mode(mode_t mode, char out[11])
+    {
+        out[0] = filetype(mode);
+        out[1] = (mode & S_IRUSR) ? 'r' : '-';
+        out[2] = (mode & S_IWUSR) ? 'w' : '-';
+        out[3] = (mode & S_ISUID) ? ((mode & S_IXUSR) ? 's' : 'S') : ((mode & S_IXUSR) ? 'x' : '-');
+        out[4] = (mode & S_IRGRP) ? 'r' : '-';
+        out[5] = (mode & S_IWGRP) ? 'w' : '-';
+        out[6] = (mode & S_ISGID) ? ((mode & S_IXGRP) ? 's' : 'S') : ((mode & S_IXGRP) ? 'x' : '-');
+        out[7] = (mode & S_IROTH) ? 'r' : '-';
+        out[8] = (mode & S_IWOTH) ? 'w' : '-';
+        // FIXME: Support the sticky bit.
+        out[9] = (mode & S_IXOTH) ? 'x' : '-';
+        out[10] = '\0';
+    }
+}