diff --git a/etstool.py b/etstool.py
index d6bf03801..2453df2a2 100644
--- a/etstool.py
+++ b/etstool.py
@@ -109,6 +109,11 @@
     "docutils"
 }
 
+# NOTE : pyface is always installed from source
+source_dependencies = {
+    "traits": "git+http://github.com/enthought/traits.git#egg=traits",
+}
+
 # Additional toolkit-independent dependencies for demo testing
 test_dependencies = {
     "apptools",