diff --git a/txnbuild/signer_summary.go b/txnbuild/signer_summary.go
new file mode 100644
index 0000000000..269e65a8f7
--- /dev/null
+++ b/txnbuild/signer_summary.go
@@ -0,0 +1,4 @@
+package txnbuild
+
+// SignerSummary is a map of signers to their weights.
+type SignerSummary map[string]int32
diff --git a/txnbuild/transaction.go b/txnbuild/transaction.go
index 23142ac198..d9aff3f669 100644
--- a/txnbuild/transaction.go
+++ b/txnbuild/transaction.go
@@ -492,9 +492,6 @@ func ReadChallengeTx(challengeTx, serverAccountID, network string) (tx Transacti
 	return tx, clientAccountID, nil
 }
 
-// SignerSummary is a map of signers to their weights.
-type SignerSummary map[string]int32
-
 // VerifyChallengeTxThreshold verifies that for a SEP 10 challenge transaction
 // all signatures on the transaction are accounted for and that the signatures
 // meet a threshold on an account. A transaction is verified if it is signed by