diff --git a/doc/api/pymongo/index.rst b/doc/api/pymongo/index.rst
index 2f436f99c..4baa3878f 100644
--- a/doc/api/pymongo/index.rst
+++ b/doc/api/pymongo/index.rst
@@ -9,6 +9,8 @@
 
       Alias for :class:`pymongo.connection.Connection`.
 
+   .. autofunction:: has_c
+
 Sub-modules:
 
 .. toctree::
diff --git a/pymongo/__init__.py b/pymongo/__init__.py
index 180848d3a..110dba755 100644
--- a/pymongo/__init__.py
+++ b/pymongo/__init__.py
@@ -33,3 +33,12 @@ version = "1.4+"
 
 Connection = PyMongo_Connection
 """Alias for :class:`pymongo.connection.Connection`."""
+
+def has_c():
+    """Is the C extension installed?
+    """
+    try:
+        from pymongo import _cbson
+        return True
+    except ImportError:
+        return False
diff --git a/tools/fail_if_no_c.py b/tools/fail_if_no_c.py
index 7f86e1dbe..60033b90f 100644
--- a/tools/fail_if_no_c.py
+++ b/tools/fail_if_no_c.py
@@ -20,7 +20,7 @@ Only really intended to be used by internal build scripts.
 import sys
 sys.path[0:0] = [""]
 
-try:
-    from pymongo import _cbson
-except ImportError:
+import pymongo
+
+if not pymongo.has_c():
     sys.exit("could not import _cbson")