diff --git a/.gitattributes b/.gitattributes
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+# I didn't write any of this
+*.hack -linguist-detectable
+*.html -linguist-detectable
+# These are inputs to test the assembler
+projects/06/*/*.asm -linguist-detectable
+
+*.tst linguist-vendored
+
+# What I've written:
+projects/**/*.hdl linguist-language=VHDL linguist-detectable