diff --git a/doc/transaction/grin-transaction.png b/doc/transaction/grin-transaction.png
index 5b1d6e2d..cd9dfb03 100644
Binary files a/doc/transaction/grin-transaction.png and b/doc/transaction/grin-transaction.png differ
diff --git a/doc/transaction/grin-transaction.puml b/doc/transaction/grin-transaction.puml
index 3406608c..771ec0e5 100644
--- a/doc/transaction/grin-transaction.puml
+++ b/doc/transaction/grin-transaction.puml
@@ -21,11 +21,12 @@ end note
 sender -> sender: Lock **inputs** in wallet
 sender -> sender: Store **change_output** in wallet with status "Unconfirmed"
 note left of sender
-	6: Calculate **fee**:  **((-1 * num_inputs) + (4 * num_change_outputs) + 1)* 1_000_000 nG**
+	6: Calculate **tx_weight**: MAX(-1 * **num_inputs** + 4 * **num_change_outputs** + 1, 1)
 		(+1 covers a single output on the receiver's side)
-	7: Calculate total blinding excess sum for all inputs and outputs **xS** (private scalar)
-	8: Select a random nonce **kS** (private scalar)
-	9: Multiply **xS** and **kS** by generator G to create public curve points **xSG** and **kSG**
+	7: Calculate **fee**:  **tx_weight** * 1_000_000 nG
+	8: Calculate total blinding excess sum for all inputs and outputs **xS** (private scalar)
+	9: Select a random nonce **kS** (private scalar)
+	10: Multiply **xS** and **kS** by generator G to create public curve points **xSG** and **kSG**
 end note
 sender -> recipient: **UUID**, **inputs**, **change_output**, **fee**, **lock_height**, **kSG**, **xSG** 
 == Phase 2 - Receiver Initiation ==