diff --git a/altair/_magics.py b/altair/_magics.py
index 3d2d845ac..2757df735 100644
--- a/altair/_magics.py
+++ b/altair/_magics.py
@@ -127,7 +127,7 @@ def namevar(s):
                 "Install pyyaml to parse spec as yaml"
             )
     else:
-        spec = yaml.load(cell, Loader=yaml.FullLoader)
+        spec = yaml.load(cell, Loader=yaml.SafeLoader)
 
     if data:
         spec["data"] = []
@@ -176,7 +176,7 @@ def vegalite(line, cell):
                 "Install pyyaml to parse spec as yaml"
             )
     else:
-        spec = yaml.load(cell, Loader=yaml.FullLoader)
+        spec = yaml.load(cell, Loader=yaml.SafeLoader)
 
     if args.data is not None:
         data = _get_variable(args.data)