diff --git a/src/tee/Makefile b/src/tee/Makefile
index 12c43d5..7419913 100644
--- a/src/tee/Makefile
+++ b/src/tee/Makefile
@@ -3,6 +3,12 @@
 CC=gcc
 CFLAGS=-O2 -fno-strength-reduce
 
+ifneq (sh.exe, $(SHELL))
+DEL = rm
+else
+DEL = del
+endif
+
 tee.exe: tee.o
 	$(CC) $(CFLAGS) -s -o $@ $<
 
@@ -10,6 +16,6 @@
 	$(CC) $(CFLAGS) -c $<
 
 clean:
-	- del tee.o
-	- del tee.exe
+	- $(DEL) tee.o
+	- $(DEL) tee.exe