diff --git a/buildlet/ec2.go b/buildlet/ec2.go
index 4a52b20..bb430b5 100644
--- a/buildlet/ec2.go
+++ b/buildlet/ec2.go
@@ -71,7 +71,7 @@
 	if err != nil {
 		return nil, err
 	}
-	if err = c.WaitUntilVMExists(ctx, vm.ID, opts); err != nil {
+	if err = c.waitUntilVMExists(ctx, vm.ID, opts); err != nil {
 		return nil, err
 	}
 	// once the VM is up and running then all of the configuration data is available
@@ -100,8 +100,8 @@
 	return inst, nil
 }
 
-// WaitUntilVMExists submits a request which waits until an instance exists before returning.
-func (c *EC2Client) WaitUntilVMExists(ctx context.Context, instID string, opts *VMOpts) error {
+// waitUntilVMExists submits a request which waits until an instance exists before returning.
+func (c *EC2Client) waitUntilVMExists(ctx context.Context, instID string, opts *VMOpts) error {
 	if err := c.client.WaitUntilInstanceRunning(ctx, instID); err != nil {
 		return fmt.Errorf("failed waiting for vm instance: %w", err)
 	}
diff --git a/buildlet/ec2_test.go b/buildlet/ec2_test.go
index 8fe1ae6..91137ea 100644
--- a/buildlet/ec2_test.go
+++ b/buildlet/ec2_test.go
@@ -190,7 +190,7 @@
 	if gotErr != nil {
 		t.Fatalf("createVM(ctx, %v, %v) failed with %s", vmConfig, opts, gotErr)
 	}
-	gotErr = c.WaitUntilVMExists(ctx, gotVM.ID, opts)
+	gotErr = c.waitUntilVMExists(ctx, gotVM.ID, opts)
 	if gotErr != nil {
 		t.Fatalf("WaitUntilVMExists(%v, %v, %v) failed with error %s", ctx, gotVM.ID, opts, gotErr)
 	}