diff --git a/include/zenoh_commons.h b/include/zenoh_commons.h
index 154b033a2..0264f8d8f 100644
--- a/include/zenoh_commons.h
+++ b/include/zenoh_commons.h
@@ -4149,7 +4149,7 @@ ZENOHC_API void z_task_drop(struct z_moved_task_t *this_);
 ZENOHC_API
 z_result_t z_task_init(struct z_owned_task_t *this_,
                        const struct z_task_attr_t *_attr,
-                       void (*fun)(void *arg),
+                       void *(*fun)(void *arg),
                        void *arg);
 /**
  * Joins the task and releases all allocated resources
diff --git a/src/platform/synchronization.rs b/src/platform/synchronization.rs
index d01904133..9ae338d41 100644
--- a/src/platform/synchronization.rs
+++ b/src/platform/synchronization.rs
@@ -242,7 +242,7 @@ pub extern "C" fn z_internal_task_check(this_: &z_owned_task_t) -> bool {
 }
 
 struct FunArgPair {
-    fun: unsafe extern "C" fn(arg: *mut c_void),
+    fun: unsafe extern "C" fn(arg: *mut c_void) -> *mut c_void,
     arg: *mut c_void,
 }
 
@@ -265,7 +265,7 @@ unsafe impl Send for FunArgPair {}
 pub unsafe extern "C" fn z_task_init(
     this: &mut MaybeUninit<z_owned_task_t>,
     _attr: *const z_task_attr_t,
-    fun: unsafe extern "C" fn(arg: *mut c_void),
+    fun: unsafe extern "C" fn(arg: *mut c_void) -> *mut c_void,
     arg: *mut c_void,
 ) -> result::z_result_t {
     let this = this.as_rust_type_mut_uninit();