diff --git a/external/js/cothority/spec/helpers/bctest.ts b/external/js/cothority/spec/helpers/bctest.ts
index cd718d714e..eba6863e0a 100644
--- a/external/js/cothority/spec/helpers/bctest.ts
+++ b/external/js/cothority/spec/helpers/bctest.ts
@@ -26,6 +26,7 @@ export class BCTest {
         if (BCTest.bct === undefined) {
             BCTest.bct = await BCTest.init();
         } else {
+            // Wait for 1s in case a transaction from a previous test is still being accepted.
             await new Promise((resolve) => setTimeout(resolve, 1000));
         }
 
diff --git a/external/js/cothority/src/byzcoin/client-transaction.ts b/external/js/cothority/src/byzcoin/client-transaction.ts
index 661ba7d69a..07a0fdaaab 100644
--- a/external/js/cothority/src/byzcoin/client-transaction.ts
+++ b/external/js/cothority/src/byzcoin/client-transaction.ts
@@ -116,6 +116,8 @@ export default class ClientTransaction extends Message<ClientTransaction> {
     }
 }
 
+type InstructionType = 0 | 1 | 2;
+
 /**
  * An instruction represents one action
  */
@@ -128,7 +130,7 @@ export class Instruction extends Message<Instruction> {
      * Get the type of the instruction
      * @returns the type as a number
      */
-    get type(): number {
+    get type(): InstructionType {
         if (this.spawn) {
             return Instruction.typeSpawn;
         }