diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index fbbe22e..f4dd508 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -58,3 +58,14 @@ stages:
        ENV_IS_SET: true
      setup:
        - script: touch src/setup.rs
+ # test no features
+ - template: azure/stages.yml
+   parameters:
+     minrust: false
+     codecov_token: $(CODECOV_TOKEN_SECRET)
+     prefix: "nofeat_"
+     envs:
+       ENV_IS_SET: true
+       ALLOW_NO_FEATURES: true
+     setup:
+       - script: touch src/setup.rs
diff --git a/azure/coverage.yml b/azure/coverage.yml
index 8ca589f..701c2d7 100644
--- a/azure/coverage.yml
+++ b/azure/coverage.yml
@@ -4,7 +4,7 @@ parameters:
   setup: []
   submodules: recursive
   nightly: false
-  features: '' # empty feature list is == default
+  features: []
 
 jobs:
  - job: tarpaulin
@@ -49,7 +49,13 @@ jobs:
      # Run any user-specific setup steps
      # Sadly we don't have a way of communicating the condition on has_secret
      - ${{ parameters.setup }}
-     - script: cargo tarpaulin --features "${{ parameters.features }}" --out Xml
+     # Determine what features to use
+     - bash: "if [[ -z $FEATURES ]]; then echo \"##vso[task.setvariable variable=features]\"; else echo \"##vso[task.setvariable variable=features]--features \\\"$FEATURES\\\"\"; fi"
+       name: features
+       displayName: Determine feature flags
+       env:
+         FEATURES: ${{ join(',', parameters.features) }}
+     - script: cargo tarpaulin $(features) --out Xml
        displayName: Run tarpaulin
        condition: and(succeeded(), eq('true', variables.has_secret))
        env:
diff --git a/azure/nightly-stages.yml b/azure/nightly-stages.yml
index 681dcdf..35ca302 100644
--- a/azure/nightly-stages.yml
+++ b/azure/nightly-stages.yml
@@ -6,7 +6,7 @@ parameters:
   test_ignored: false
   single_threaded: false
   check_all_features: true
-  test_features: ''
+  test_features: []
 
 stages:
  # the format here is so that we can have _two_ instances of this whole
diff --git a/azure/stages.yml b/azure/stages.yml
index ede925f..4205e1e 100644
--- a/azure/stages.yml
+++ b/azure/stages.yml
@@ -8,8 +8,8 @@ parameters:
   single_threaded: false
   nightly_coverage: false
   check_all_features: true
-  nightly_feature: ''
-  test_features: ''
+  nightly_features: []
+  test_features: []
 
 stages:
  # the format here is so that we can have _two_ instances of this whole
@@ -56,7 +56,7 @@ stages:
          setup: ${{ parameters.setup }}
          test_ignored: ${{ parameters.test_ignored }}
          single_threaded: ${{ parameters.single_threaded }}
-         nightly_feature: ${{ parameters.nightly_feature }}
+         nightly_features: ${{ parameters.nightly_features }}
          features: ${{ parameters.test_features }}
  - stage: ${{ format('{0}style', parameters.prefix) }}
    ${{ if ne(parameters.prefix, '') }}:
diff --git a/azure/test.yml b/azure/test.yml
index d7664fb..7cd71f6 100644
--- a/azure/test.yml
+++ b/azure/test.yml
@@ -6,7 +6,7 @@ parameters:
   setup: []
   test_ignored: false
   single_threaded: false
-  features: '' # empty feature list is == default
+  features: []
   services: {}
 
 jobs:
@@ -37,23 +37,28 @@ jobs:
     parameters:
       rust: ${{ parameters.rust }}
       setup: ${{ parameters.setup }}
+  - bash: "if [[ -z $FEATURES ]]; then echo \"##vso[task.setvariable variable=features]\"; else echo \"##vso[task.setvariable variable=features]--features \\\"$FEATURES\\\"\"; fi"
+    name: features
+    displayName: Determine feature flags
+    env:
+      FEATURES: ${{ join(',', parameters.features) }}
   - ${{ if ne('true', parameters.single_threaded) }}:
-    - script: cargo test --all --features "${{ parameters.features }}"
+    - script: cargo test --all $(features)
       displayName: Run tests
       env:
         ${{ insert }}: ${{ parameters.envs }}
   - ${{ if eq('true', parameters.single_threaded) }}:
-    - script: cargo test --all --features "${{ parameters.features }}" -- --test-threads=1
+    - script: cargo test --all $(features) -- --test-threads=1
       displayName: Run tests (single-threaded)
       env:
         ${{ insert }}: ${{ parameters.envs }}
   - ${{ if and(eq('true', parameters.test_ignored), ne('true', parameters.single_threaded)) }}:
-    - script: cargo test --all --features "${{ parameters.features }}" -- --ignored
+    - script: cargo test --all $(features) -- --ignored
       displayName: Run ignored tests
       env:
         ${{ insert }}: ${{ parameters.envs }}
   - ${{ if and(eq('true', parameters.test_ignored), eq('true', parameters.single_threaded)) }}:
-    - script: cargo test --all --features "${{ parameters.features }}" -- --ignored --test-threads=1
+    - script: cargo test --all $(features) -- --ignored --test-threads=1
       displayName: Run ignored tests (single-threaded)
       env:
         ${{ insert }}: ${{ parameters.envs }}
diff --git a/azure/tests.yml b/azure/tests.yml
index bbab2de..693e41c 100644
--- a/azure/tests.yml
+++ b/azure/tests.yml
@@ -3,8 +3,8 @@ parameters:
   setup: []
   test_ignored: false
   single_threaded: false
-  nightly_feature: ''
-  features: ''
+  nightly_features: []
+  features: []
 
 jobs:
  - template: test.yml
@@ -34,4 +34,6 @@ jobs:
      setup: ${{ parameters.setup }}
      test_ignored: ${{ parameters.test_ignored }}
      single_threaded: ${{ parameters.single_threaded }}
-     features: "${{ parameters.features }},${{ parameters.nightly_feature }}"
+     features:
+       - ${{ parameters.features }}
+       - ${{ parameters.nightly_feature }}
diff --git a/docs/configuration.md b/docs/configuration.md
index 389b848..d6ff5ae 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -72,13 +72,13 @@ Set this parameter to `true` to also run tests [marked with
 stages:
  - template: azure/stages.yml@templates
    parameters:
-     test_features: <string> = ''
-     nightly_feature: <string> = ''
+     test_features: <[string]> = []
+     nightly_features: <[string]> = []
 ```
 
 If this parameter is set, it is passed along with `--features` to `cargo
 test`. This is useful if you have non-default features that you'd like
-to test on CI. You can also set `nightly_feature` which will only be
+to test on CI. You can also set `nightly_features` which will only be
 included when run on nightly, though do note that since nightly tests
 are always allowed to fail, you will only see yellow CI if these tests
 fail. If you have features like this, you _probably_ also want to
@@ -90,7 +90,7 @@ features as `subcrate/feature` as described in [this
 issue](https://github.com/rust-lang/cargo/issues/5015). There is not
 currently a way to disabling default features for CI tests.
 
-**`nightly_feature is not supported (or needed) on `nightly-stages.yml`.**
+**`nightly_features is not supported (or needed) on `nightly-stages.yml`.**
 
 ### Single-threaded test execution
 
diff --git a/docs/custom.md b/docs/custom.md
index 234776c..3e90661 100644
--- a/docs/custom.md
+++ b/docs/custom.md
@@ -159,8 +159,8 @@ You can pass the parameter `envs: {...}` to pass [environment
 variables](configuration.md#environment-variables), and `setup: [...]`
 to run [additional setup
 steps](configuration.md#additional-setup-steps). You can also pass
-`features` and/or `nightly_feature` to include additional cargo features
-when running the tests. `nightly_feature` will only be included on runs
+`features` and/or `nightly_features` to include additional cargo features
+when running the tests. `nightly_features` will only be included on runs
 with the nightly compiler. See the [test docs](#test) for details.
 
 ### Test
@@ -173,7 +173,7 @@ parameters:
   allow_fail: <bool> = false
   test_ignored: <bool> = false
   single_threaded: <bool> = false
-  features: <string> = ''
+  features: <[string]> = []
   envs:
     NAME: value
   services:
@@ -194,7 +194,7 @@ nightly versions of the compiler. To run tests [marked with
 set `test_ignored: true`. To run tests with
 [`--test-threads=1`](https://doc.rust-lang.org/book/ch11-02-running-tests.html#running-tests-in-parallel-or-consecutively),
 set `single_threaded: true`. To run tests with particular features
-enabled, pass `features: "feat1,feat2,subcrate/feat3"`.
+enabled, pass `features: [feat1,feat2,subcrate/feat3]`.
 To spin up additional [service
 containers](https://docs.microsoft.com/en-us/azure/devops/pipelines/process/service-containers?view=azure-devops&tabs=yaml),
 pass them in `services` (though note that these will generally only work
diff --git a/src/lib.rs b/src/lib.rs
index 94d2376..61388ce 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -18,7 +18,9 @@ fn require_env() {
 
 #[cfg(all(test, not(feature = "ci")))]
 fn must_exist() {
-    panic!("ci feature was not enabled for test run");
+    if !std::env::var("ALLOW_NO_FEATURES").is_ok() {
+        panic!("ci feature was not enabled for test run");
+    }
 }
 
 #[cfg(all(test, feature = "ci"))]