diff --git a/core/config.mk b/core/config.mk
index 586f403..f35b44e 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -8,6 +8,10 @@
 # directly.
 SHELL := /bin/bash
 
+# Tell python not to spam the source tree with .pyc files.  This
+# only has an effect on python 2.6 and above.
+export PYTHONDONTWRITEBYTECODE := 1
+
 # Standard source directories.
 SRC_DOCS:= $(TOPDIR)docs
 # TODO: Enforce some kind of layering; only add include paths