diff --git a/.golangci.yml b/.golangci.yml
index 58bf167f26c..de823f35625 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -69,6 +69,7 @@ linters-settings:
       - G109
       - G112
       - G114
+      - G302
 
 run:
   timeout: 10m
diff --git a/pkg/mimirtool/commands/config.go b/pkg/mimirtool/commands/config.go
index d91c526481a..2dbd99f1941 100644
--- a/pkg/mimirtool/commands/config.go
+++ b/pkg/mimirtool/commands/config.go
@@ -107,7 +107,7 @@ func (c *ConfigCommand) output(yamlContents []byte, flags []string, notices conf
 		if path == "" {
 			return defaultWriter, func() {}, nil
 		}
-		outWriter, err := os.OpenFile(path, os.O_TRUNC|os.O_CREATE|os.O_WRONLY, 0666)
+		outWriter, err := os.OpenFile(path, os.O_TRUNC|os.O_CREATE|os.O_WRONLY, 0600)
 		if err != nil {
 			return nil, nil, errors.Wrap(err, "could not open "+path)
 		}
diff --git a/pkg/util/activitytracker/activity_tracker.go b/pkg/util/activitytracker/activity_tracker.go
index 745cc504030..01d8d9a7400 100644
--- a/pkg/util/activitytracker/activity_tracker.go
+++ b/pkg/util/activitytracker/activity_tracker.go
@@ -172,7 +172,7 @@ func trimEntryToSize(entry string, size int) string {
 }
 
 func getMappedFile(filename string, filesize int) (*os.File, mmap.MMap, error) {
-	file, err := os.OpenFile(filename, os.O_CREATE|os.O_RDWR|os.O_TRUNC, 0666)
+	file, err := os.OpenFile(filename, os.O_CREATE|os.O_RDWR|os.O_TRUNC, 0600)
 	if err != nil {
 		return nil, nil, errors.Wrap(err, "failed to create activity file")
 	}
diff --git a/pkg/util/shutdownmarker/shutdown_marker.go b/pkg/util/shutdownmarker/shutdown_marker.go
index a07a64f5493..9eb83bfac45 100644
--- a/pkg/util/shutdownmarker/shutdown_marker.go
+++ b/pkg/util/shutdownmarker/shutdown_marker.go
@@ -29,7 +29,7 @@ func Remove(p string) error {
 		return err
 	}
 
-	dir, err := os.OpenFile(path.Dir(p), os.O_RDONLY, 0777)
+	dir, err := os.OpenFile(path.Dir(p), os.O_RDONLY, 0600) // mode doesn't matter since we're not passing os.O_CREATE
 	if err != nil {
 		return err
 	}