diff --git a/Makefile b/Makefile
index dcb442f..6c3f6a8 100644
--- a/Makefile
+++ b/Makefile
@@ -22,15 +22,13 @@ flake8:
 
 isort-check:
 	isort --case-sensitive --check-only --line-width=88 --multi-line=3 \
-		  --project=rmakers --thirdparty=abjad --thirdparty=abjadext \
-		  --thirdparty=baca --thirdparty=ply --thirdparty=uqbar \
-		  --trailing-comma --use-parentheses .
+		  --project=rmakers --thirdparty=abjad --thirdparty=baca \
+		  --thirdparty=ply --thirdparty=uqbar --trailing-comma --use-parentheses .
 
 isort-reformat:
 	isort --case-sensitive --line-width=88 --multi-line=3 \
-	      --project=rmakers --thirdparty=abjad --thirdparty=abjadext \
-		  --thirdparty=baca --thirdparty=ply --thirdparty=uqbar \
-		  --trailing-comma --use-parentheses .
+	      --project=rmakers --thirdparty=abjad --thirdparty=baca \
+		  --thirdparty=ply --thirdparty=uqbar --trailing-comma --use-parentheses .
 
 mypy:
 	mypy source