diff --git a/Implementierung/Makefile b/Implementierung/Makefile
index 0ad1c96..5d0ea38 100644
--- a/Implementierung/Makefile
+++ b/Implementierung/Makefile
@@ -30,7 +30,7 @@ md2: ${OBJ}
 	${CC} -o $@ $(OBJ) ${LDFLAGS}
 
 t/%:
-	@mkdir t
+	@mkdir -p t
 	@echo
 	@echo "=== Generating ${subst t/,,$@}MB of random data... ==="
 	dd if=/dev/random of=$@ bs=1M count=${subst t/,,$@} status=progress