diff --git a/dev/buildbot/master/master.cfg b/dev/buildbot/master/master.cfg
index 77b81d62..d370a6a7 100644
--- a/dev/buildbot/master/master.cfg
+++ b/dev/buildbot/master/master.cfg
@@ -126,7 +126,7 @@ def python_slave(key, platform, conda_env, cmake_args = [], cmake_env = {}, buil
     if platform.find('OSX') > -1:
         source = ['source']
     else:
-        source = [
+        source = []
     
     factory.addStep(ShellCommand(command = ' '.join(source + ["activate",conda_env,"&&","cmake", "..", "-DCOOLPROP_PYTHON_"+key+"=ON"]+cmake_args),
                                  env = cmake_env,