diff --git a/docs/source/_images/Makefile b/docs/source/_images/Makefile
index 086821c60..dc75c97c9 100644
--- a/docs/source/_images/Makefile
+++ b/docs/source/_images/Makefile
@@ -32,8 +32,9 @@ FORCE:
 TEX_FILES := $(shell find . -name *.tex)
 all_tex: $(TEX_FILES:.tex=.pdf) $(TEX_FILES:.tex=.svg)
 
+# limit output size to US letter (same as latexpdf output) to avoid oversize error
 %.pdf: %.dot
-	$(FAKETIME) dot -Tpdf -Gsize="9x15!" -o $@ $<
+	$(FAKETIME) dot -Tpdf -Gsize="8.5,11" -o $@ $<
 
 %.pdf: %.tex
 	cd $(@D) && $(FAKETIME) pdflatex $(<F) --interaction=nonstopmode