diff --git a/code/datums/mutations/speech.dm b/code/datums/mutations/speech.dm
index 091c3abedf..3b4b38bbcc 100644
--- a/code/datums/mutations/speech.dm
+++ b/code/datums/mutations/speech.dm
@@ -98,6 +98,7 @@
 /datum/mutation/human/unintelligible
 	name = "Unintelligible"
 	quality = NEGATIVE
+	dna_block = NON_SCANNABLE
 	text_gain_indication = "<span class='danger'>You can't seem to form any coherent thoughts!</span>"
 	text_lose_indication = "<span class='danger'>Your mind feels more clear.</span>"