diff --git a/setup.py b/setup.py
index 1b1fde6e6d..43475e05ad 100755
--- a/setup.py
+++ b/setup.py
@@ -1159,6 +1159,9 @@ def _from_conda(self,
         success = True
         condaexe = ["conda", "install", "-y"]
         if channels is not None:
+            if len(channels) > 1 and "defaults" in channels:
+                logger.debug("Setting default channel to lowest priority")
+                channels = [c for c in channels if c != "defaults"] + ["defaults"]
             for channel in channels:
                 condaexe.extend(["-c", channel])
             condaexe.append("--override-channels")