diff --git a/checkout.go b/checkout.go
index e0c067e..a2e312b 100644
--- a/checkout.go
+++ b/checkout.go
@@ -44,7 +44,8 @@ type CheckoutOpts struct {
 	FileMode        os.FileMode      // Default is 0644 or 0755 as dictated by blob
 	FileOpenFlags   int              // Default is O_CREAT | O_TRUNC | O_WRONLY
 	TargetDirectory string           // Alternative checkout path to workdir
-	Paths			[]string
+	Paths           []string
+	Baseline        *Tree
 }
 
 func checkoutOptionsFromC(c *C.git_checkout_options) CheckoutOpts {
@@ -90,6 +91,10 @@ func populateCheckoutOpts(ptr *C.git_checkout_options, opts *CheckoutOpts) *C.gi
 		ptr.paths.count = C.size_t(len(opts.Paths))
 	}
 
+	if opts.Baseline != nil {
+		ptr.baseline = opts.Baseline.cast_ptr
+	}
+
 	return ptr
 }
 
@@ -156,4 +161,4 @@ func (v *Repository) CheckoutTree(tree *Tree, opts *CheckoutOpts) error {
 	}
 
 	return nil
-}
\ No newline at end of file
+}