diff --git a/core/thread/thread.odin b/core/thread/thread.odin
index b98f4c07c..ffa47faa7 100644
--- a/core/thread/thread.odin
+++ b/core/thread/thread.odin
@@ -57,75 +57,89 @@ run_with_data :: proc(data: rawptr, fn: proc(data: rawptr), init_context: Maybe(
 }
 
 run_with_poly_data :: proc(data: $T, fn: proc(data: T), init_context: Maybe(runtime.Context) = nil, priority := Thread_Priority.Normal)
-	where intrinsics.type_is_pointer(T) || size_of(T) == size_of(rawptr) {
+	where size_of(T) <= size_of(rawptr) {
 	thread_proc :: proc(t: ^Thread) {
-		fn := cast(proc(rawptr))t.data;
+		fn := cast(proc(T))t.data;
 		assert(t.user_index >= 1);
-		data := t.user_args[0];
+		data := (^T)(&t.user_args[0])^;
 		fn(data);
 		destroy(t);
 	}
 	t := create(thread_proc, priority);
 	t.data = rawptr(fn);
 	t.user_index = 1;
-	t.user_args[0] = transmute(rawptr)data;
+	data := data;
+	mem.copy(&t.user_args[0], &data, size_of(data));
 	t.init_context = init_context;
 	start(t);
 }
 
 run_with_poly_data2 :: proc(arg1: $T1, arg2: $T2, fn: proc(T1, T2), init_context: Maybe(runtime.Context) = nil, priority := Thread_Priority.Normal)
-	where intrinsics.type_is_pointer(T1) || size_of(T1) == size_of(rawptr),
-	      intrinsics.type_is_pointer(T2) || size_of(T2) == size_of(rawptr) {
+	where size_of(T1) <= size_of(rawptr),
+	      size_of(T2) <= size_of(rawptr) {
 	thread_proc :: proc(t: ^Thread) {
-		fn := cast(proc(rawptr, rawptr))t.data;
+		fn := cast(proc(T1, T2))t.data;
 		assert(t.user_index >= 2);
-		fn(t.user_args[0], t.user_args[1]);
+		arg1 := (^T1)(&t.user_args[0])^;
+		arg2 := (^T2)(&t.user_args[1])^;
+		fn(arg1, arg2);
 		destroy(t);
 	}
 	t := create(thread_proc, priority);
 	t.data = rawptr(fn);
 	t.user_index = 2;
-	t.user_args[0] = transmute(rawptr)arg1;
-	t.user_args[1] = transmute(rawptr)arg2;
+	arg1, arg2 := arg1, arg2;
+	mem.copy(&t.user_args[0], &arg1, size_of(arg1));
+	mem.copy(&t.user_args[1], &arg2, size_of(arg2));
 	t.init_context = init_context;
 	start(t);
 }
 
 run_with_poly_data3 :: proc(arg1: $T1, arg2: $T2, arg3: $T3, fn: proc(arg1: T1, arg2: T2, arg3: T3), init_context: Maybe(runtime.Context) = nil, priority := Thread_Priority.Normal)
-	where intrinsics.type_is_pointer(T1) || size_of(T1) == size_of(rawptr),
-	      intrinsics.type_is_pointer(T2) || size_of(T2) == size_of(rawptr),
-	      intrinsics.type_is_pointer(T3) || size_of(T3) == size_of(rawptr) {
+	where size_of(T1) <= size_of(rawptr),
+	      size_of(T2) <= size_of(rawptr),
+	      size_of(T3) <= size_of(rawptr) {
 	thread_proc :: proc(t: ^Thread) {
-		fn := cast(proc(rawptr, rawptr, rawptr))t.data;
+		fn := cast(proc(T1, T2, T3))t.data;
 		assert(t.user_index >= 3);
-		fn(t.user_args[0], t.user_args[1], t.user_args[2]);
+		arg1 := (^T1)(&t.user_args[0])^;
+		arg2 := (^T2)(&t.user_args[1])^;
+		arg3 := (^T2)(&t.user_args[2])^;
+		fn(arg1, arg2, arg3);
 		destroy(t);
 	}
 	t := create(thread_proc, priority);
 	t.data = rawptr(fn);
 	t.user_index = 3;
-	t.user_args[0] = transmute(rawptr)arg1;
-	t.user_args[1] = transmute(rawptr)arg2;
-	t.user_args[2] = transmute(rawptr)arg3;
+	arg1, arg2, arg3 := arg1, arg2, arg3;
+	mem.copy(&t.user_args[0], &arg1, size_of(arg1));
+	mem.copy(&t.user_args[1], &arg2, size_of(arg2));
+	mem.copy(&t.user_args[2], &arg3, size_of(arg3));
 	t.init_context = init_context;
 	start(t);
 }
 run_with_poly_data4 :: proc(arg1: $T1, arg2: $T2, arg3: $T3, arg4: $T4, fn: proc(arg1: T1, arg2: T2, arg3: T3, arg4: T4), init_context: Maybe(runtime.Context) = nil, priority := Thread_Priority.Normal)
-	where intrinsics.type_is_pointer(T1) || size_of(T1) == size_of(rawptr),
-	      intrinsics.type_is_pointer(T2) || size_of(T2) == size_of(rawptr),
-	      intrinsics.type_is_pointer(T3) || size_of(T3) == size_of(rawptr) {
+	where size_of(T1) <= size_of(rawptr),
+	      size_of(T2) <= size_of(rawptr),
+	      size_of(T3) <= size_of(rawptr) {
 	thread_proc :: proc(t: ^Thread) {
-		fn := cast(proc(rawptr, rawptr, rawptr))t.data;
-		assert(t.user_index >= 3);
-		fn(t.user_args[0], t.user_args[1], t.user_args[2]);
+		fn := cast(proc(T1, T2, T3, T4))t.data;
+		assert(t.user_index >= 4);
+		arg1 := (^T1)(&t.user_args[0])^;
+		arg2 := (^T2)(&t.user_args[1])^;
+		arg3 := (^T2)(&t.user_args[2])^;
+		arg4 := (^T2)(&t.user_args[3])^;
+		fn(arg1, arg2, arg3, arg4);
 		destroy(t);
 	}
 	t := create(thread_proc, priority);
 	t.data = rawptr(fn);
-	t.user_index = 3;
-	t.user_args[0] = transmute(rawptr)arg1;
-	t.user_args[1] = transmute(rawptr)arg2;
-	t.user_args[2] = transmute(rawptr)arg3;
+	t.user_index = 4;
+	arg1, arg2, arg3, arg4 := arg1, arg2, arg3, arg4;
+	mem.copy(&t.user_args[0], &arg1, size_of(arg1));
+	mem.copy(&t.user_args[1], &arg2, size_of(arg2));
+	mem.copy(&t.user_args[2], &arg3, size_of(arg3));
+	mem.copy(&t.user_args[3], &arg4, size_of(arg4));
 	t.init_context = init_context;
 	start(t);
 }