diff --git a/pkg_resources/pkg_resources.py b/pkg_resources/pkg_resources.py
index b7488f04..8dd1897e 100644
--- a/pkg_resources/pkg_resources.py
+++ b/pkg_resources/pkg_resources.py
@@ -1,9 +1,27 @@
-import os
-import os.path
+import uio
+
+c = {}
 
 def resource_stream(package, resource):
-    p = __import__(package)
-    d = os.path.dirname(p.__file__)
-    if d[0] != "/":
-        d = os.getcwd() + "/" + d
-    return open(d + "/" + resource, "rb")
+    if package not in c:
+        try:
+            if package:
+                p = __import__(package + ".R", None, None, True)
+            else:
+                p = __import__("R")
+            c[package] = p.R
+        except ImportError:
+            if package:
+                p = __import__(package)
+                d = p.__path__
+            else:
+                d = "."
+            if d[0] != "/":
+                import uos
+                d = uos.getcwd() + "/" + d
+            c[package] = d + "/"
+
+    p = c[package]
+    if isinstance(p, dict):
+        return uio.BytesIO(p[resource])
+    return open(p + resource, "rb")