diff --git a/wave/Makefile b/wave/Makefile
new file mode 100644
index 0000000..80f3fe1
--- /dev/null
+++ b/wave/Makefile
@@ -0,0 +1,17 @@
+all: sim
+sim: pdmout_test.ghw square_test.ghw wave_test.ghw
+
+sim_sources = pdmout_test.vhdl square_test.vhdl wave_test.vhdl
+sources = pdmout.vhdl square.vhdl wave.vhdl pdm.vhdl
+
+
+%.ghw: work-obj93.cf
+	ghdl -r $* --wave=$@
+
+
+work-obj93.cf: $(sim_sources) $(sources)
+	ghdl -a $^
+
+PHONY: sim
+
+.PRECIOUS: test.ghw
diff --git a/wave/makefile b/wave/makefile
deleted file mode 100644
index 23410f3..0000000
--- a/wave/makefile
+++ /dev/null
@@ -1,17 +0,0 @@
-all: sim
-sim: pdmout_test.ghw square_test.ghw
-
-sim_sources = pdmout_test.vhdl square_test.vhdl
-sources = pdmout.vhdl square.vhdl
-
-
-%.ghw: work-obj93.cf
-	ghdl -r $* --wave=$@
-
-
-work-obj93.cf: $(sim_sources) $(sources)
-	ghdl -a $^
-
-PHONY: sim
-
-.PRECIOUS: test.ghw