diff --git a/x/mlxrunner/cache/recurrent.go b/x/mlxrunner/cache/recurrent.go
index 2c02ff3d4..a3c7f90d8 100644
--- a/x/mlxrunner/cache/recurrent.go
+++ b/x/mlxrunner/cache/recurrent.go
@@ -22,14 +22,9 @@ func (c *RecurrentCache) setStateRaw(old, v *mlx.Array) *mlx.Array {
 	if v == nil || !v.Valid() {
 		return old
 	}
-	if old == v {
-		return old
-	}
 
 	mlx.Pin(v)
-	if old != nil && old != v {
-		mlx.Unpin(old)
-	}
+	mlx.Unpin(old)
 
 	return v
 }
@@ -38,9 +33,6 @@ func (c *RecurrentCache) setStateDetached(old, v *mlx.Array, ensureContiguous bo
 	if v == nil || !v.Valid() {
 		return old
 	}
-	if old == v {
-		return old
-	}
 
 	root := v
 	if ensureContiguous {
@@ -49,9 +41,7 @@ func (c *RecurrentCache) setStateDetached(old, v *mlx.Array, ensureContiguous bo
 	detached := root.Clone()
 
 	mlx.Pin(detached)
-	if old != nil && old != detached {
-		mlx.Unpin(old)
-	}
+	mlx.Unpin(old)
 
 	return detached
 }
diff --git a/x/mlxrunner/mlx/array.go b/x/mlxrunner/mlx/array.go
index de91813fc..5604da24a 100644
--- a/x/mlxrunner/mlx/array.go
+++ b/x/mlxrunner/mlx/array.go
@@ -137,6 +137,9 @@ func Unpin(s ...*Array) {
 	for _, t := range s {
 		if t != nil {
 			t.pinned--
+			if t.pinned < 0 {
+				panic(fmt.Sprintf("mlx.Unpin: negative pin count on array %q", t.name))
+			}
 		}
 	}
 }
@@ -261,7 +264,7 @@ func LogArrays() {
 
 	for _, t := range arrays {
 		nb := t.NumBytes()
-		logutil.Trace(fmt.Sprintf("tensor %-60s %5s %5s %v", t.name, t.DType(), PrettyBytes(nb), t.Dims()))
+		logutil.Trace(fmt.Sprintf("tensor %-60s %5s %5s pinned=%d %v", t.name, t.DType(), PrettyBytes(nb), t.pinned, t.Dims()))
 	}
 	logutil.Trace(fmt.Sprintf("tensors total: %d, size: %s", len(arrays), PrettyBytes(ActiveMemory())))
 }