diff --git a/README.md b/README.md
index 55a8d06..ae2bf9c 100644
--- a/README.md
+++ b/README.md
@@ -18,12 +18,15 @@ include plantuml-toolset/wsd.mk
 After that you can invoke it in a number of ways:
 
 ```shell
-# Find all *.wsd in the current directory and make svg's out of them
+# Find all *.wsd in the current directory recursively and make svg's out of them
 $ make
 
 # Same but make png's
 $ make FORMAT=png
 
+# Same but make both png's and svg's
+$ make FORMAT="png svg"
+
 # Make examples/conversation.png
 $ make FORMAT=png examples/conversation.wsd
 ```
diff --git a/wsd.mk b/wsd.mk
index 08553d5..7f23b18 100644
--- a/wsd.mk
+++ b/wsd.mk
@@ -1,9 +1,9 @@
 FORMAT ?= svg
-SOURCES = $(wildcard ./*.wsd)
-TARGETS = $(patsubst %.wsd,%.$(FORMAT),$(SOURCES))
+SOURCES = $(wildcard *.wsd **/*.wsd)
+TARGETS = $(foreach fmt, $(FORMAT), $(patsubst %.wsd,%.$(fmt),$(SOURCES)))
 STYLE ?= style.isvg
 
-.PHONY: all clean toolset force
+.PHONY: all clean install-toolset force
 
 validate = test -s $@ || { rm $@; exit 1; }