diff --git a/bip-0174.mediawiki b/bip-0174.mediawiki
index 874af144..bf331454 100644
--- a/bip-0174.mediawiki
+++ b/bip-0174.mediawiki
@@ -235,7 +235,7 @@ The currently defined per-input types are defined as follows:
 | <tt><pubkey></tt>
 | The public key which corresponds to this signature.
 | <tt><signature></tt>
-| The signature as would be pushed to the stack from a scriptSig or witness.
+| The signature as would be pushed to the stack from a scriptSig or witness. The signature should be a valid ECDSA signature corresponding to the pubkey that would return true when verified and not a value that would return false or be invalid otherwise (such as a NULLDUMMY).
 |
 |
 | 0, 2