diff --git a/api/src/instruction.rs b/api/src/instruction.rs
index f6d081b..01c9ff0 100644
--- a/api/src/instruction.rs
+++ b/api/src/instruction.rs
@@ -247,8 +247,13 @@ pub fn crown(signer: Pubkey, current_top_staker: Pubkey) -> Instruction {
 }
 
 /// Builds a mine instruction.
-pub fn mine(signer: Pubkey, bus: Pubkey, solution: Solution) -> Instruction {
-    let proof = Pubkey::find_program_address(&[PROOF, signer.as_ref()], &crate::id()).0;
+pub fn mine(
+    signer: Pubkey,
+    proof_authority: Pubkey,
+    bus: Pubkey,
+    solution: Solution,
+) -> Instruction {
+    let proof = Pubkey::find_program_address(&[PROOF, proof_authority.as_ref()], &crate::id()).0;
     Instruction {
         program_id: crate::id(),
         accounts: vec![