diff --git a/src/proofofwork.py b/src/proofofwork.py
index f2c32c06..2238eaec 100644
--- a/src/proofofwork.py
+++ b/src/proofofwork.py
@@ -4,7 +4,7 @@
 import hashlib
 from struct import unpack, pack
 import sys
-from shared import config
+from shared import config, frozen
 #import os
 
 def _set_idle():
@@ -71,7 +71,7 @@ def _doFastPoW(target, initialHash):
         time.sleep(0.2)
 
 def run(target, initialHash):
-    if 'linux' in sys.platform:
+    if not frozen:
         return _doFastPoW(target, initialHash)
     else:
         return _doSafePoW(target, initialHash)
diff --git a/src/shared.py b/src/shared.py
index d2b82d11..13d57445 100644
--- a/src/shared.py
+++ b/src/shared.py
@@ -74,6 +74,11 @@ networkDefaultPayloadLengthExtraBytes = 14000 #To make sending short messages a
 # namecoin integration to "namecoind".
 namecoinDefaultRpcPort = "8336"
 
+# When using py2exe or py2app, the variable frozen is added to the sys
+# namespace.  This can be used to setup a different code path for 
+# binary distributions vs source distributions.
+frozen = getattr(sys,'frozen', None)
+
 def isInSqlInventory(hash):
     t = (hash,)
     shared.sqlLock.acquire()