diff --git a/unix-ffi/email.message/manifest.py b/unix-ffi/email.message/manifest.py
index 7b75ee7ac..7814dfe4b 100644
--- a/unix-ffi/email.message/manifest.py
+++ b/unix-ffi/email.message/manifest.py
@@ -1,7 +1,7 @@
 metadata(version="0.5.3")
 
 require("re", unix_ffi=True)
-require("uu")
+require("uu", unix_ffi=True)
 require("base64")
 require("binascii")
 require("email.utils", unix_ffi=True)
diff --git a/unix-ffi/glob/manifest.py b/unix-ffi/glob/manifest.py
index 622289bca..64f5233c5 100644
--- a/unix-ffi/glob/manifest.py
+++ b/unix-ffi/glob/manifest.py
@@ -1,7 +1,7 @@
 metadata(version="0.5.2")
 
 require("os", unix_ffi=True)
-require("os-path")
+require("os-path", unix_ffi=True)
 require("re", unix_ffi=True)
 require("fnmatch")
 
diff --git a/unix-ffi/os-path/manifest.py b/unix-ffi/os-path/manifest.py
new file mode 100644
index 000000000..5390333dc
--- /dev/null
+++ b/unix-ffi/os-path/manifest.py
@@ -0,0 +1,6 @@
+metadata(version="0.1.4")
+
+# Originally written by Paul Sokolovsky.
+
+require("os", unix_ffi=True)
+package("os", base_path="../../python-stdlib/os-path")
diff --git a/unix-ffi/os/os/__init__.py b/unix-ffi/os/os/__init__.py
index 3cca078f9..54fdc246a 100644
--- a/unix-ffi/os/os/__init__.py
+++ b/unix-ffi/os/os/__init__.py
@@ -5,6 +5,12 @@
 import ffilib
 import uos
 
+# Provide optional dependencies (which may be installed separately).
+try:
+    from . import path
+except ImportError:
+    pass
+
 R_OK = const(4)
 W_OK = const(2)
 X_OK = const(1)
diff --git a/unix-ffi/uu/manifest.py b/unix-ffi/uu/manifest.py
new file mode 100644
index 000000000..f2213418f
--- /dev/null
+++ b/unix-ffi/uu/manifest.py
@@ -0,0 +1,6 @@
+metadata(version="0.5.1")
+
+require("binascii")
+require("os-path", unix_ffi=True)
+
+module("uu.py", base_path="../../python-stdlib/uu")