diff --git a/tinygrad/codegen/kernel.py b/tinygrad/codegen/kernel.py
index 6ba081a0a2..fc85f6f40a 100644
--- a/tinygrad/codegen/kernel.py
+++ b/tinygrad/codegen/kernel.py
@@ -482,9 +482,9 @@ class Kernel:
         k.apply_opt(Opt(OptOps.UPCAST, 0, 128))
 
       # make all non first dimensions local
-      if getenv("MULTICORE", 1):
+      if getenv("MULTICORE", 0) and len(k.full_shape) >= 1 and k.full_shape[0] > 1:
         if k.full_shape[0]%2 == 1: k.apply_opt(Opt(OptOps.PADTO, 0, 2))
-        k.apply_opt(Opt(OptOps.LOCAL, 0, k.full_shape[0]//2))
+        if k.full_shape[0] > 2: k.apply_opt(Opt(OptOps.LOCAL, 0, k.full_shape[0]//2))
         for i in range(1, k.first_reduce-1): k.apply_opt(Opt(OptOps.LOCAL, 1, 0))
       else:
         for i in range(1, k.first_reduce): k.apply_opt(Opt(OptOps.LOCAL, 1, 0))