diff --git a/.test-conda-env-py3-macos.yml b/.test-conda-env-py3-macos.yml
index 3db6f243aff2d05b2d79704897394184b8f67304..901576dcf85d5fae32db5acb200702e2ad73c352 100644
--- a/.test-conda-env-py3-macos.yml
+++ b/.test-conda-env-py3-macos.yml
@@ -1,7 +1,7 @@
 name: test-conda-env-py3-macos
 channels:
 - conda-forge
-- defaults
+- nodefaults
 dependencies:
 - git
 - conda-forge::numpy
diff --git a/.test-conda-env-py3.yml b/.test-conda-env-py3.yml
index 2571d81dac9220e24c72e83efe224a7a8b20cebd..748855b09faf2accacd8b0970597d4732740a2a4 100644
--- a/.test-conda-env-py3.yml
+++ b/.test-conda-env-py3.yml
@@ -1,7 +1,7 @@
 name: test-conda-env-py3
 channels:
 - conda-forge
-- defaults
+- nodefaults
 dependencies:
 - git
 - scipy