Fixes.
diff --git a/sram_spice.py b/sram_spice.py
index 0649b9e..4a310c1 100755
--- a/sram_spice.py
+++ b/sram_spice.py
@@ -32,7 +32,8 @@
     d = os.path.join(dst_dir, ddir, f"{dbase}.{dext}")
 
     with open(d, "w") as f:
-        f.write(header)
+        if not data.startswith(header):
+            f.write(header)
         f.write(data)
 
     print("Created", s, "from", d)