diff --git a/Makefile b/Makefile
index 8048f5915aa829e250c5e9fd40d76393de4975b1..e37dd90fd26f3e052b06cd3b8b28711766b660cd 100644
--- a/Makefile
+++ b/Makefile
@@ -1111,3 +1111,6 @@ check-alembic: makeopts
 
 FORCE:
 
+# This only stops targets within the root Makefile from building in parallel.
+.NOTPARALLEL:
+