diff --git a/README.md b/README.md
index ddd0b79..0109b0b 100644
--- a/README.md
+++ b/README.md
@@ -54,6 +54,9 @@ setting CFLAGS and LDFLAGS.
 Known Issues
 ------------
 
+- Code coverage appears to be worse than it is.  When launching the
+  subprocesses, their coverage does not get measured.  Patches to fix
+  this would be greatly appreciated.
 - Possible memory leak for each connection
   Error message is: Task exception was never retrieved
   See the commented out assertion at the end of test_clientkeymismatch