diff --git a/packages/core/js-client/src/api.ts b/packages/core/js-client/src/api.ts
index 87015af5..ab618d23 100644
--- a/packages/core/js-client/src/api.ts
+++ b/packages/core/js-client/src/api.ts
@@ -99,6 +99,9 @@ export const v5_callFunction = async (
     }),
   );
 
+  const returnTypeVoid =
+    def.arrow.codomain.tag === "nil" || def.arrow.codomain.items.length === 0;
+
   const params = {
     peer,
     args: callArgs,
@@ -108,6 +111,7 @@ export const v5_callFunction = async (
   const result = await callAquaFunction({
     script,
     ...params,
+    fireAndForget: returnTypeVoid,
   });
 
   const valueSchema =
diff --git a/packages/core/js-client/src/compilerSupport/callFunction.ts b/packages/core/js-client/src/compilerSupport/callFunction.ts
index acefb8fc..2d4970f8 100644
--- a/packages/core/js-client/src/compilerSupport/callFunction.ts
+++ b/packages/core/js-client/src/compilerSupport/callFunction.ts
@@ -50,7 +50,7 @@ export type CallAquaFunctionArgs = {
   config: CallAquaFunctionConfig | undefined;
   peer: FluencePeer;
   args: { [key: string]: JSONValue | ArgCallbackFunction };
-  fireAndForget?: boolean;
+  fireAndForget: boolean | undefined;
 };
 
 export type CallAquaFunctionConfig = {