diff --git a/tests/core/pyspec/eth_consensus_specs/test/helpers/deposits.py b/tests/core/pyspec/eth_consensus_specs/test/helpers/deposits.py
index c609e9a5e54..9040d05446b 100644
--- a/tests/core/pyspec/eth_consensus_specs/test/helpers/deposits.py
+++ b/tests/core/pyspec/eth_consensus_specs/test/helpers/deposits.py
@@ -63,7 +63,8 @@ def sign_deposit_data(spec, deposit_data, privkey, fork_version=None):
     else:
         domain = spec.compute_domain(spec.DOMAIN_DEPOSIT)
     signing_root = spec.compute_signing_root(deposit_message, domain)
-    deposit_data.signature = bls.Sign(privkey, signing_root)
+    # Real signature even with BLS verification disabled, its validity is state data
+    deposit_data.signature = bls.SignUnconditionally(privkey, signing_root)
 
 
 def build_deposit(spec, deposit_data_list, pubkey, privkey, amount, withdrawal_credentials, signed):
diff --git a/tests/core/pyspec/eth_consensus_specs/utils/bls.py b/tests/core/pyspec/eth_consensus_specs/utils/bls.py
index b077d610065..d0ce13030c7 100644
--- a/tests/core/pyspec/eth_consensus_specs/utils/bls.py
+++ b/tests/core/pyspec/eth_consensus_specs/utils/bls.py
@@ -179,12 +179,21 @@ def Aggregate(signatures):
     return aggregate.to_compressed_bytes()
 
 
-@only_with_bls(alt_return=STUB_SIGNATURE)
-def Sign(SK, message):
+# Deposit signatures must be computed even when BLS is inactive: unlike other
+# signatures, an invalid deposit signature causes the deposit to be ignored
+# rather than failing the state transition, so its validity is reflected in
+# the beacon state, which clients must be able to reproduce regardless of the
+# `bls_setting` in use.
+def SignUnconditionally(SK, message):
     signature_point = _hash_to_G2(message) * _sk_to_scalar(SK)
     return signature_point.to_compressed_bytes()
 
 
+@only_with_bls(alt_return=STUB_SIGNATURE)
+def Sign(SK, message):
+    return SignUnconditionally(SK, message)
+
+
 # Pubkey aggregation must be computed even when BLS is inactive: unlike
 # signature verification, its result is data written into the beacon state
 # (e.g. `next_sync_committee.aggregate_pubkey`), which clients must be able