diff --git a/pkg/cluster/cluster_file.go b/pkg/cluster/cluster_file.go
index 306b3f2..e1deb11 100644
--- a/pkg/cluster/cluster_file.go
+++ b/pkg/cluster/cluster_file.go
@@ -33,7 +33,11 @@ func (m *Cluster) openWriter(name string, flags int, args ...any) (io.WriteClose
 		return nil, err
 	}
 
-	return f.(io.WriteCloser), nil
+	if f, ok := f.(io.WriteCloser); ok {
+		return f, nil
+	}
+
+	panic("unreachable")
 }
 
 // ReadFile reads a file from the cluster's config directory
diff --git a/pkg/cluster/machine_file.go b/pkg/cluster/machine_file.go
index a6e90eb..40dde3a 100644
--- a/pkg/cluster/machine_file.go
+++ b/pkg/cluster/machine_file.go
@@ -34,7 +34,11 @@ func (m *Machine) openWriter(name string, flags int, args ...any) (io.WriteClose
 		return nil, err
 	}
 
-	return f.(io.WriteCloser), nil
+	if f, ok := f.(io.WriteCloser); ok {
+		return f, nil
+	}
+
+	panic("unreachable")
 }
 
 // RemoveFile deletes a file from the machine's config directory