diff --git a/lecture1/Julia is fast.ipynb b/lecture1/Julia is fast.ipynb
index 40f7f293..61205673 100644
--- a/lecture1/Julia is fast.ipynb	
+++ b/lecture1/Julia is fast.ipynb	
@@ -4478,7 +4478,7 @@
    "source": [
     "function mysum(A)   \n",
     "    s = 0.0  # s = zero(eltype(A))\n",
-    "    #@inbounds @simd for a in A\n",
+    "    #@simd for a in A\n",
     "    for a in A\n",
     "        s += a\n",
     "    end\n",
@@ -4568,7 +4568,7 @@
    "source": [
     "function myfastsum(A)   \n",
     "    s = 0.0  # s = zero(eltype(A))\n",
-    "    @inbounds @simd for a in A  # <-- don't check bounds, parallel on processor\n",
+    "    @simd for a in A  # <-- don't check bounds, parallel on processor\n",
     "        s += a\n",
     "    end\n",
     "    s\n",