diff --git a/lib/spack/spack/config.py b/lib/spack/spack/config.py
index 21e08ff66632f69705e8c6274e950ddc0b6f70c3..9488e49ab9be5e4d3f060ec304bdfcdf23e6c896 100644
--- a/lib/spack/spack/config.py
+++ b/lib/spack/spack/config.py
@@ -269,10 +269,10 @@
 
 
 def validate_section_name(section):
-    """Raise a ValueError if the section is not a valid section."""
+    """Exit if the section is not a valid section."""
     if section not in section_schemas:
-        raise ValueError("Invalid config section: '%s'.  Options are %s"
-                         % (section, section_schemas))
+        tty.die("Invalid config section: '%s'. Options are: %s"
+                % (section, " ".join(section_schemas.keys())))
 
 
 def extend_with_default(validator_class):