diff --git a/test/unit/test_viz.py b/test/unit/test_viz.py
index b2d2973803..b7edb9d2c6 100644
--- a/test/unit/test_viz.py
+++ b/test/unit/test_viz.py
@@ -359,7 +359,7 @@ def load_profile(lst:list[ProfileEvent]) -> dict:
       for _ in range(event_count):
         alloc, ts, key = u("<BII")
         if alloc: v["events"].append({"event":"alloc", "ts":ts, "key":key, "arg": {"dtype":strings[u("<I")[0]], "sz":u("<Q")[0]}})
-        else: v["events"].append({"event":"free", "ts":ts, "key":key, "arg": {"users":[u("<IIBB") for _ in range(u("<I")[0])]}})
+        else: v["events"].append({"event":"free", "ts":ts, "key":key, "arg": {"users":[u("<IIIB") for _ in range(u("<I")[0])]}})
   return {"dur":total_dur, "peak":global_peak, "layout":layout, "markers":markers}
 
 class TestVizProfiler(BaseTestViz):
diff --git a/tinygrad/viz/js/index.js b/tinygrad/viz/js/index.js
index 0372920221..ceec360e80 100644
--- a/tinygrad/viz/js/index.js
+++ b/tinygrad/viz/js/index.js
@@ -357,7 +357,7 @@ async function renderProfiler(path, unit, opts) {
           x += 1; y += nbytes; valueMap.set(ts, y);
         } else {
           const free = buf_shapes.get(key);
-          free.users = Array.from({ length: u32() }, () => ({shape:shapeMap.get(u32()), repr:strings[u32()], num:u8(), mode:u8()}));
+          free.users = Array.from({ length: u32() }, () => ({shape:shapeMap.get(u32()), repr:strings[u32()], num:u32(), mode:u8()}));
           timestamps.push(ts); valueMap.set(ts, y);
           x += 1; y -= free.nbytes;
           free.x.push(x);
diff --git a/tinygrad/viz/serve.py b/tinygrad/viz/serve.py
index b20b3524e2..068b3c1d1c 100755
--- a/tinygrad/viz/serve.py
+++ b/tinygrad/viz/serve.py
@@ -178,12 +178,12 @@ def timeline_layout(dev_events:list[tuple[int, int, float, DevEvent]], start_ts:
   return struct.pack("<BI", 0, len(events))+b"".join(events) if events else None
 
 def encode_mem_free(key:int, ts:int, execs:list[ProfilePointEvent], scache:dict) -> bytes:
-  ei_encoding:list[tuple[int, int, int, int]] = [] # <[u32, u32, u8, u8] [run id, display name, buffer number and mode (2 = r/w, 1 = w, 0 = r)]
+  ei_encoding:list[tuple[int, int, int, int]] = [] # <[u32, u32, u32, u8] [run id, display name, buffer number and mode (2 = r/w, 1 = w, 0 = r)]
   for e in execs:
     num = next(i for i,k in enumerate(e.arg["bufs"]) if k == key)
     mode = 2 if (num in e.arg["inputs"] and num in e.arg["outputs"]) else 1 if (num in e.arg["outputs"]) else 0
     ei_encoding.append((e.key, enum_str(e.arg["name"], scache), num, mode))
-  return struct.pack("<BIII", 0, ts, key, len(ei_encoding))+b"".join(struct.pack("<IIBB", *t) for t in ei_encoding)
+  return struct.pack("<BIII", 0, ts, key, len(ei_encoding))+b"".join(struct.pack("<IIIB", *t) for t in ei_encoding)
 
 def mem_layout(dev_events:list[tuple[int, int, float, DevEvent]], start_ts:int, end_ts:int, peaks:list[int], dtype_size:dict[str, int],
                scache:dict[str, int]) -> bytes|None: