diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 1444ca5..e1af050 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.0'
+          - '1.6'
           - '1'
           - 'nightly'
         os:
diff --git a/src/simshow.jl b/src/simshow.jl
index 2820575..598bc94 100644
--- a/src/simshow.jl
+++ b/src/simshow.jl
@@ -57,7 +57,10 @@ function simshow(arr::AbstractArray{T};
     Tr = real(T)
     # scale abs to 1
     absarr = abs.(arr)
-    absarr ./= maximum(absarr)
+    m = maximum(absarr)
+    if !iszero(m)
+        absarr ./= maximum(absarr)
+    end
 
     if !isone(γ)
         absarr .= absarr .^ γ