diff --git a/.github/workflows/example-3.yml b/.github/workflows/example-3.yml
index cbdecc6b..bf93bd87 100644
--- a/.github/workflows/example-3.yml
+++ b/.github/workflows/example-3.yml
@@ -27,3 +27,23 @@ jobs:
           conda info
           conda list
           printenv | sort
+
+
+  example-3-no-name:
+    name: Ex3-no-name Linux
+    runs-on: 'ubuntu-latest'
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ./
+        with:
+          activate-environment: anaconda-client-env
+          environment-file: etc/example-environment-no-name.yml
+          python-version: 3.8
+          condarc-file: etc/example-condarc.yml
+          auto-activate-base: false
+          auto-update-conda: true
+      - shell: bash -l {0}
+        run: |
+          conda info
+          conda list
+          printenv | sort
diff --git a/dist/setup/index.js b/dist/setup/index.js
index 342e4672..f0637086 100644
--- a/dist/setup/index.js
+++ b/dist/setup/index.js
@@ -21947,6 +21947,7 @@ function setupMiniconda(installerUrl, minicondaVersion, architecture, condaVersi
             if (environmentFile) {
                 let environmentYaml;
                 let condaAction;
+                let activateEnvironmentToUse;
                 try {
                     const sourceEnvironmentPath = path.join(process.env["GITHUB_WORKSPACE"] || "", environmentFile);
                     environmentYaml = yield yaml.safeLoad(fs.readFileSync(sourceEnvironmentPath, "utf8"));
@@ -21958,18 +21959,26 @@ function setupMiniconda(installerUrl, minicondaVersion, architecture, condaVersi
                     environmentYaml["name"] !== undefined &&
                     environmentYaml["name"] !== activateEnvironment) {
                     condaAction = "create";
+                    activateEnvironmentToUse = environmentYaml["name"];
                     utils.consoleLog(`Creating conda environment from yaml file...`);
-                    core.warning('The environment name on "environment-file" is not the same as "enviroment-activate"!');
+                    core.warning('The environment name on "environment-file" is not the same as "enviroment-activate", using "environment-file"!');
                 }
                 else if (activateEnvironment &&
                     activateEnvironment === environmentYaml["name"]) {
                     utils.consoleLog(`Updating conda environment from yaml file...`);
                     condaAction = "update";
+                    activateEnvironmentToUse = activateEnvironment;
+                }
+                else if (activateEnvironment && environmentYaml["name"] === undefined) {
+                    core.warning('The environment name on "environment-file" is not defined, using "enviroment-activate"!');
+                    condaAction = "update";
+                    activateEnvironmentToUse = activateEnvironment;
                 }
                 else {
+                    activateEnvironmentToUse = activateEnvironment;
                     condaAction = "create";
                 }
-                result = yield condaCommand(`env ${condaAction} -f ${environmentFile}`, useBundled, useMamba);
+                result = yield condaCommand(`env ${condaAction} --file ${environmentFile} --name ${activateEnvironmentToUse}`, useBundled, useMamba);
                 if (!result.ok)
                     return result;
             }
diff --git a/etc/example-environment-no-name.yml b/etc/example-environment-no-name.yml
new file mode 100644
index 00000000..227056d9
--- /dev/null
+++ b/etc/example-environment-no-name.yml
@@ -0,0 +1,3 @@
+dependencies:
+  - black
+  - anaconda-client
diff --git a/src/setup.ts b/src/setup.ts
index bdbb8b3a..a3eebcfb 100644
--- a/src/setup.ts
+++ b/src/setup.ts
@@ -826,6 +826,7 @@ async function setupMiniconda(
     if (environmentFile) {
       let environmentYaml: TEnvironment;
       let condaAction: string;
+      let activateEnvironmentToUse: string;
       try {
         const sourceEnvironmentPath: string = path.join(
           process.env["GITHUB_WORKSPACE"] || "",
@@ -843,9 +844,10 @@ async function setupMiniconda(
         environmentYaml["name"] !== activateEnvironment
       ) {
         condaAction = "create";
+        activateEnvironmentToUse = environmentYaml["name"];
         utils.consoleLog(`Creating conda environment from yaml file...`);
         core.warning(
-          'The environment name on "environment-file" is not the same as "enviroment-activate"!'
+          'The environment name on "environment-file" is not the same as "enviroment-activate", using "environment-file"!'
         );
       } else if (
         activateEnvironment &&
@@ -853,11 +855,19 @@ async function setupMiniconda(
       ) {
         utils.consoleLog(`Updating conda environment from yaml file...`);
         condaAction = "update";
+        activateEnvironmentToUse = activateEnvironment;
+      } else if (activateEnvironment && environmentYaml["name"] === undefined) {
+        core.warning(
+          'The environment name on "environment-file" is not defined, using "enviroment-activate"!'
+        );
+        condaAction = "update";
+        activateEnvironmentToUse = activateEnvironment;
       } else {
+        activateEnvironmentToUse = activateEnvironment;
         condaAction = "create";
       }
       result = await condaCommand(
-        `env ${condaAction} -f ${environmentFile}`,
+        `env ${condaAction} --file ${environmentFile} --name ${activateEnvironmentToUse}`,
         useBundled,
         useMamba
       );