diff --git a/clustering/Makefile b/clustering/Makefile
index c4095421a..298479f1c 100644
--- a/clustering/Makefile
+++ b/clustering/Makefile
@@ -10,7 +10,7 @@ watch:
 	fswatch *.seqdiag | xargs -n 1 sh -c "make || true"
 
 $(FONT):
-	curl -sLo $@ https://googlefontdirectory.googlecode.com/hg/apache/droidsansmono/$(FONT).ttf
+	curl -sLo $@ https://googlefontdirectory.googlecode.com/hg/apache/droidsansmono/$(FONT)
 
 %.png: %.seqdiag $(FONT)
-	seqdiag -a -f '$(FONT)' $<
+	seqdiag --no-transparency -a -f '$(FONT)' $<
diff --git a/clustering/dynamic.png b/clustering/dynamic.png
index 9f2ff9dbc..92b40fee3 100644
Binary files a/clustering/dynamic.png and b/clustering/dynamic.png differ
diff --git a/clustering/static.png b/clustering/static.png
index a01ebbe88..bcdeca7e6 100644
Binary files a/clustering/static.png and b/clustering/static.png differ