diff --git a/lib/spack/spack/main.py b/lib/spack/spack/main.py
index 1aaf447324..334311fcf6 100644
--- a/lib/spack/spack/main.py
+++ b/lib/spack/spack/main.py
@@ -467,7 +467,7 @@ def setup_main_options(args):
 
     # Use the spack config command to handle parsing the config strings
     for config_var in (args.config_vars or []):
-        spack.config.add(path=config_var, scope="command_line")
+        spack.config.add(fullpath=config_var, scope="command_line")
 
     # when to use color (takes always, auto, or never)
     color.set_color_when(args.color)