diff --git a/README.md b/README.md
index 7c7d9d6..54195da 100644
--- a/README.md
+++ b/README.md
@@ -67,14 +67,14 @@ Add these parameters under the `with` section of the `uses` step in the workflow
 | `paths`                         | Limit to specific files or directories (separated by newlines). | |
 | `exclude_imports`               | Exclude files imported by the target modules. | False |
 | `exclude_paths`                 | Exclude specific files or directories, e.g. "proto/a/a.proto", "proto/a" (separated by newlines). | |
-| `pr_comment`                    | Comment the results on the pull request. The workflow and job name combination must be unique. | Only on pull requests |
+| `pr_comment`                    | Comment the results on the pull request. The workflow and job name combination must be unique. | Only on pull requests (non forks) |
 | `format`                        | Whether to run the formatting step. | Runs on pushes to Git PR |
 | `lint`                          | Whether to run the linting step. | Runs on pushes to Git PR |
 | `breaking`                      | Whether to run the breaking change detection step. | Runs on pushes to Git PR |
 | `breaking_against`              | [Input](https://buf.build/docs/reference/inputs) to compare against. | Base of the PR or the commit before the event |
-| `push`                          | Whether to run the push step. | Runs on Git pushes |
+| `push`                          | Whether to run the push step. | Runs on Git pushes (non forks) |
 | `push_disable_create`           | Disables repository creation if it does not exist. | False |
-| `archive`                       | Whether to run the archive step. | Runs on Git deletes |
+| `archive`                       | Whether to run the archive step. | Runs on Git deletes (non forks) |
 | `setup_only`                    | Setup only the `buf` environment, optionally logging into the BSR, but without executing other commands. | |
 | `github_actor`                  | GitHub actor for API requests. | Actor from GitHub context |
 | `github_token`                  | GitHub token for API requests. Ensures requests aren't rate limited | Token from GitHub context |
diff --git a/action.yml b/action.yml
index 3566fad..aac3a10 100644
--- a/action.yml
+++ b/action.yml
@@ -56,8 +56,9 @@ inputs:
   pr_comment:
     description: |-
       Comment on the pull request with the results of each step. The workflow and job name combination must be unique.
+      Only runs on pull requests, for non forked repositories.
     required: false
-    default: ${{ github.event_name == 'pull_request' }}
+    default: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name == github.repository }}
 
   input:
     description: |-
@@ -115,7 +116,7 @@ inputs:
 
   push:
     description: |-
-      Whether to run the push step. Runs by default on pushes.
+      Whether to run the push step. Runs by default on pushes, for non forked repositories.
     required: false
     default: ${{ github.event_name == 'push' }}
   push_disable_create:
@@ -126,7 +127,7 @@ inputs:
 
   archive:
     description: |-
-      Whether to run the archive step. Runs by default on deletes.
+      Whether to run the archive step. Runs by default on deletes, for non forked repositories.
     required: false
     default: ${{ github.event_name == 'delete' }}