diff --git a/sch2fig/Makefile b/sch2fig/Makefile
index 87d78f0..17dffe2 100644
--- a/sch2fig/Makefile
+++ b/sch2fig/Makefile
@@ -22,7 +22,7 @@ LIBS = -lm `pkg-config --libs cairo`
 
 include ../common/Makefile.c-common
 
-.PHONY:		test neo900 sch test diff view newref
+.PHONY:		test neo900 sch test testref png pngref diff view newref
 
 all::		$(NAME)
 
@@ -44,8 +44,19 @@ test:		$(NAME)
 testref:
 		./$(NAME) test.lib test.sch | fig2dev -L png -m 2 >ref.png
 
+png:
+		./$(NAME) test.lib test.sch -- cairo
+		[ ! -r pngref.png ] || \
+		    compare -metric AE pngref.png test.png _diff.png || \
+		    qiv -t -R -D _diff.png pngref.png test.png
+
+pngref:
+		./$(NAME) test.lib test.sch -- cairo
+		mv test.png pngref.png
+
 clean::
 		rm -f out.fig _out.png _diff.png
+		rm -f test.png
 
 #----- Render Neo900 schematics -----------------------------------------------