diff --git a/electrum/__init__.py b/electrum/__init__.py
index 793f2930c..e94ac78ac 100644
--- a/electrum/__init__.py
+++ b/electrum/__init__.py
@@ -46,3 +46,10 @@ except AssertionError:
 else:
     raise ImportError("Running with asserts disabled. Refusing to continue. Exiting...")
 
+
+# Check that os.urandom works
+import zlib
+length = len(zlib.compress(os.urandom(1000)))
+if length <= 900:
+    raise ImportError("Broken PRNG. Refusing to continue. Exiting...")
+
diff --git a/electrum/rsakey.py b/electrum/rsakey.py
index da87076fe..5266e9cf9 100644
--- a/electrum/rsakey.py
+++ b/electrum/rsakey.py
@@ -46,10 +46,6 @@ def SHA1(x):
 # PRNG Functions
 # **************************************************************************
 
-# Check that os.urandom works
-import zlib
-length = len(zlib.compress(os.urandom(1000)))
-assert length > 900
 
 def getRandomBytes(howMany):
     b = bytearray(os.urandom(howMany))