diff --git a/Makefile b/Makefile
index 2dc91e8..25b307a 100644
--- a/Makefile
+++ b/Makefile
@@ -28,10 +28,10 @@ readme:
 lint_package:
 	${RSCRIPT} -e "lintr::lint_package()"
 
+# use: `make style_file FILE=stuff.R`
+# ("R/" is prepended); accepts 1 file only
 style_file:
-	# use: make style_file FILE=stuff.R ("R/" is prepended)
-	# accepts 1 file only
-	${RSCRIPT} -e "styler::style_file('${FILE_TARGET}')"
+	${RSCRIPT} -e 'styler::style_file(${FILE_TARGET})'
 
 style_package:
 	${RSCRIPT} -e "styler::style_pkg()"