diff --git a/pkg/tree/builder.go b/pkg/tree/builder.go
index 62ed3b34..d98e651b 100644
--- a/pkg/tree/builder.go
+++ b/pkg/tree/builder.go
@@ -26,5 +26,5 @@ type Builder interface {
 	GetDatabase() pkg.PackageDatabase
 	WithDatabase(d pkg.PackageDatabase)
 
-	GetSourcePath() string
+	GetSourcePath() []string
 }
diff --git a/pkg/tree/compiler_recipe.go b/pkg/tree/compiler_recipe.go
index 84e1776d..bea03a3b 100644
--- a/pkg/tree/compiler_recipe.go
+++ b/pkg/tree/compiler_recipe.go
@@ -45,7 +45,7 @@ type CompilerRecipe struct {
 
 func (r *CompilerRecipe) Load(path string) error {
 
-	r.SourcePath = path
+	r.SourcePath = append(r.SourcePath, path)
 	//tmpfile, err := ioutil.TempFile("", "luet")
 	//if err != nil {
 	//	return err
@@ -111,4 +111,4 @@ func (r *CompilerRecipe) Load(path string) error {
 
 func (r *CompilerRecipe) GetDatabase() pkg.PackageDatabase   { return r.Database }
 func (r *CompilerRecipe) WithDatabase(d pkg.PackageDatabase) { r.Database = d }
-func (r *CompilerRecipe) GetSourcePath() string              { return r.SourcePath }
+func (r *CompilerRecipe) GetSourcePath() []string            { return r.SourcePath }
diff --git a/pkg/tree/installer_recipe.go b/pkg/tree/installer_recipe.go
index 7b581b21..5e81dcc7 100644
--- a/pkg/tree/installer_recipe.go
+++ b/pkg/tree/installer_recipe.go
@@ -40,7 +40,7 @@ func NewInstallerRecipe(db pkg.PackageDatabase) Builder {
 
 // InstallerRecipe is the "general" reciper for Trees
 type InstallerRecipe struct {
-	SourcePath string
+	SourcePath []string
 	Database   pkg.PackageDatabase
 }
 
@@ -74,7 +74,7 @@ func (r *InstallerRecipe) Load(path string) error {
 	// if err != nil {
 	// 	return err
 	// }
-	r.SourcePath = path
+	r.SourcePath = append(r.SourcePath, path)
 
 	//r.Tree().SetPackageSet(pkg.NewBoltDatabase(tmpfile.Name()))
 	// TODO: Handle cleaning after? Cleanup implemented in GetPackageSet().Clean()
@@ -114,4 +114,4 @@ func (r *InstallerRecipe) Load(path string) error {
 
 func (r *InstallerRecipe) GetDatabase() pkg.PackageDatabase   { return r.Database }
 func (r *InstallerRecipe) WithDatabase(d pkg.PackageDatabase) { r.Database = d }
-func (r *InstallerRecipe) GetSourcePath() string              { return r.SourcePath }
+func (r *InstallerRecipe) GetSourcePath() []string            { return r.SourcePath }
diff --git a/pkg/tree/recipes.go b/pkg/tree/recipes.go
index e99825bf..052cfcd6 100644
--- a/pkg/tree/recipes.go
+++ b/pkg/tree/recipes.go
@@ -37,7 +37,7 @@ func NewGeneralRecipe(db pkg.PackageDatabase) Builder { return &Recipe{Database:
 
 // Recipe is the "general" reciper for Trees
 type Recipe struct {
-	SourcePath string
+	SourcePath []string
 	Database   pkg.PackageDatabase
 }
 
@@ -65,7 +65,7 @@ func (r *Recipe) Load(path string) error {
 	// if err != nil {
 	// 	return err
 	// }
-	r.SourcePath = path
+	r.SourcePath = append(r.SourcePath, path)
 
 	if r.Database == nil {
 		r.Database = pkg.NewInMemoryDatabase(false)
@@ -109,4 +109,4 @@ func (r *Recipe) Load(path string) error {
 
 func (r *Recipe) GetDatabase() pkg.PackageDatabase   { return r.Database }
 func (r *Recipe) WithDatabase(d pkg.PackageDatabase) { r.Database = d }
-func (r *Recipe) GetSourcePath() string              { return r.SourcePath }
+func (r *Recipe) GetSourcePath() []string            { return r.SourcePath }
diff --git a/pkg/tree/tree_test.go b/pkg/tree/tree_test.go
index 0d6cc725..c54c232e 100644
--- a/pkg/tree/tree_test.go
+++ b/pkg/tree/tree_test.go
@@ -96,4 +96,60 @@ var _ = Describe("Tree", func() {
 		})
 	})
 
+	Context("Multiple trees", func() {
+		It("Merges", func() {
+			for index := 0; index < 300; index++ { // Just to make sure we don't have false positives
+				db := pkg.NewInMemoryDatabase(false)
+				generalRecipe := NewCompilerRecipe(db)
+				tmpdir, err := ioutil.TempDir("", "package")
+				Expect(err).ToNot(HaveOccurred())
+				defer os.RemoveAll(tmpdir) // clean up
+
+				err = generalRecipe.Load("../../tests/fixtures/buildableseed")
+				Expect(err).ToNot(HaveOccurred())
+
+				Expect(len(generalRecipe.GetDatabase().World())).To(Equal(4))
+
+				err = generalRecipe.Load("../../tests/fixtures/layers")
+				Expect(err).ToNot(HaveOccurred())
+
+				Expect(len(generalRecipe.GetDatabase().World())).To(Equal(6))
+
+				extra, err := generalRecipe.GetDatabase().FindPackage(&pkg.DefaultPackage{Name: "extra", Category: "layer", Version: "1.0"})
+				Expect(err).ToNot(HaveOccurred())
+				Expect(extra).ToNot(BeNil())
+
+				D, err := generalRecipe.GetDatabase().FindPackage(&pkg.DefaultPackage{Name: "d", Category: "test", Version: "1.0"})
+				Expect(err).ToNot(HaveOccurred())
+
+				Expect(D.GetRequires()[0].GetName()).To(Equal("c"))
+				CfromD, err := generalRecipe.GetDatabase().FindPackage(D.GetRequires()[0])
+				Expect(err).ToNot(HaveOccurred())
+
+				Expect(len(CfromD.GetRequires()) != 0).To(BeTrue())
+				Expect(CfromD.GetRequires()[0].GetName()).To(Equal("b"))
+
+				s := solver.NewSolver(pkg.NewInMemoryDatabase(false), generalRecipe.GetDatabase(), db)
+
+				Dd, err := generalRecipe.GetDatabase().FindPackage(&pkg.DefaultPackage{Name: "d", Category: "test", Version: "1.0"})
+				Expect(err).ToNot(HaveOccurred())
+
+				solution, err := s.Install([]pkg.Package{Dd})
+				Expect(err).ToNot(HaveOccurred())
+
+				solution = solution.Order(generalRecipe.GetDatabase(), Dd.GetFingerPrint())
+				pack, err := generalRecipe.GetDatabase().FindPackage(&pkg.DefaultPackage{Name: "a", Category: "test", Version: "1.0"})
+				Expect(err).ToNot(HaveOccurred())
+
+				base, err := generalRecipe.GetDatabase().FindPackage(&pkg.DefaultPackage{Name: "base", Category: "layer", Version: "0.2"})
+				Expect(err).ToNot(HaveOccurred())
+				Expect(solution).To(ContainElement(solver.PackageAssert{Package: pack.(*pkg.DefaultPackage), Value: false}))
+				Expect(solution).To(ContainElement(solver.PackageAssert{Package: D.(*pkg.DefaultPackage), Value: true}))
+				Expect(solution).To(ContainElement(solver.PackageAssert{Package: extra.(*pkg.DefaultPackage), Value: false}))
+				Expect(solution).To(ContainElement(solver.PackageAssert{Package: base.(*pkg.DefaultPackage), Value: false}))
+				Expect(len(solution)).To(Equal(6))
+			}
+		})
+	})
+
 })