diff --git a/otto.sh b/otto.sh
index 515840c..8765c50 100755
--- a/otto.sh
+++ b/otto.sh
@@ -122,10 +122,10 @@ add_new_module () {
     echo "copying & customizing template files..."
     
     sed "s/module_name/${modname}/" $MODULE_DIR/module_name.c >  $modsrc_dir/${modname}.c
-    sed "3s/todays_date/$(date +%Y)/" $modsrc_dir/${modname}.c > $modsrc_dir/${modname}.c 
+    sed -i'' "3s/todays_date/$(date +%Y)/" $modsrc_dir/${modname}.c
 
     sed "s/module_name/${modname_cap}/" $MODULE_DIR/module_name.h > $modsrc_dir/${modname}.h  
-    sed "3s/todays_date/$(date +%Y)/" $modsrc_dir/${modname}.h > $modsrc_dir/${modname}.h 
+    sed -i'' "3s/todays_date/$(date +%Y)/" $modsrc_dir/${modname}.h
 
     sed "s/module_name/${modname}/" $MODULE_DIR/CMakeLists.txt > $modsrc_dir/CMakeLists.txt