diff --git a/docs/images/Makefile b/docs/images/Makefile
--- a/docs/images/Makefile
+++ b/docs/images/Makefile
@@ -3,7 +3,7 @@
 PNGs = $(patsubst %.puml,%.png,$(PUMLs))
 SVGs = $(patsubst %.puml,%.svg,$(PUMLs))
 
-all: $(PNGs) $(PDFs) $(SVGs)
+all: $(PNGs) $(SVGs)
 
 %.pdf: %.puml
 	plantuml -Tpdf $<
@@ -14,7 +14,6 @@
 %.svg: %.puml
 	plantuml -Tsvg $<
 
-
 .PHONY: clean
 
 clean: