diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7d9b597..6e29024 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,6 +11,7 @@ jobs:
         version:
           - '1.0'
           - '1.4'
+          - '1.5.0-beta1'
           - 'nightly'
         os:
           - ubuntu-latest
@@ -18,6 +19,12 @@ jobs:
           - windows-latest
         arch:
           - x64
+        exclude:
+          # See https://github.com/marketplace/actions/setup-julia-environment
+          - {os: 'macOS-latest', version: '1.4'}
+          - {os: 'macOS-latest', version: 'nightly'}
+          - {os: 'windows-latest', version: '1.4'}
+          - {os: 'windows-latest', version: 'nightly'}
     steps:
       - uses: actions/checkout@v2
       - uses: julia-actions/setup-julia@v1
diff --git a/test/runtests.jl b/test/runtests.jl
index 1f51655..c657c7c 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -11,13 +11,13 @@ using Test
           opcompose(inv, tuple)
 end
 
-if VERSION >= v"1.5"  # TODO: remove this once Compact adds it
+if VERSION >= v"1.5.0-DEV.56"  # TODO: remove this once Compact adds it
 @testset "unary" begin
     @test ∘(tuple) === compose(tuple) === var"⨟"(tuple) === opcompose(tuple) === tuple
 end
 end  # if
 
-if VERSION >= v"1.5"
+if VERSION >= v"1.5.0-DEV.302"  # for ⨟
     include("test_julia15.jl")
 end