diff --git a/Gododir/main.go b/Gododir/main.go
index 0733602c..57a0f34e 100644
--- a/Gododir/main.go
+++ b/Gododir/main.go
@@ -10,6 +10,7 @@ import (
 	"github.com/8thlight/vulcanizedb/core"
 	"github.com/8thlight/vulcanizedb/geth"
 	"github.com/8thlight/vulcanizedb/observers"
+	"github.com/8thlight/vulcanizedb/repositories"
 	"github.com/jmoiron/sqlx"
 	do "gopkg.in/godo.v2"
 )
@@ -31,7 +32,8 @@ func startBlockchainListener(cfg config.Config) {
 	if err != nil {
 		log.Fatalf("Error connecting to DB: %v\n", err)
 	}
-	dbObserver := (observers.BlockchainDBObserver{Db: db})
+	repository := repositories.NewPostgres(db)
+	dbObserver := observers.NewBlockchainDbObserver(repository)
 	listener := blockchain_listener.NewBlockchainListener(blockchain, []core.BlockchainObserver{
 		loggingObserver,
 		dbObserver,
diff --git a/blockchain_listener/blockchain_listener_test.go b/blockchain_listener/blockchain_listener_test.go
index c64eb5c4..9f55db94 100644
--- a/blockchain_listener/blockchain_listener_test.go
+++ b/blockchain_listener/blockchain_listener_test.go
@@ -11,7 +11,7 @@ import (
 var _ = Describe("Blockchain listeners", func() {
 
 	It("starts with no blocks", func(done Done) {
-		observer := fakes.NewFakeBlockchainObserverTwo()
+		observer := fakes.NewFakeBlockchainObserver()
 		blockchain := &fakes.Blockchain{}
 
 		blockchain_listener.NewBlockchainListener(blockchain, []core.BlockchainObserver{observer})
@@ -21,7 +21,7 @@ var _ = Describe("Blockchain listeners", func() {
 	}, 1)
 
 	It("sees when one block was added", func(done Done) {
-		observer := fakes.NewFakeBlockchainObserverTwo()
+		observer := fakes.NewFakeBlockchainObserver()
 		blockchain := &fakes.Blockchain{}
 		listener := blockchain_listener.NewBlockchainListener(blockchain, []core.BlockchainObserver{observer})
 		go listener.Start()
@@ -37,7 +37,7 @@ var _ = Describe("Blockchain listeners", func() {
 	}, 1)
 
 	It("sees a second block", func(done Done) {
-		observer := fakes.NewFakeBlockchainObserverTwo()
+		observer := fakes.NewFakeBlockchainObserver()
 		blockchain := &fakes.Blockchain{}
 		listener := blockchain_listener.NewBlockchainListener(blockchain, []core.BlockchainObserver{observer})
 		go listener.Start()
@@ -55,7 +55,7 @@ var _ = Describe("Blockchain listeners", func() {
 	}, 1)
 
 	It("stops listening", func(done Done) {
-		observer := fakes.NewFakeBlockchainObserverTwo()
+		observer := fakes.NewFakeBlockchainObserver()
 		blockchain := &fakes.Blockchain{}
 		listener := blockchain_listener.NewBlockchainListener(blockchain, []core.BlockchainObserver{observer})
 		go listener.Start()
diff --git a/fakes/blockchain_observer.go b/fakes/blockchain_observer.go
index add572e2..8dd444c0 100644
--- a/fakes/blockchain_observer.go
+++ b/fakes/blockchain_observer.go
@@ -11,7 +11,7 @@ func (observer *BlockchainObserver) LastBlock() core.Block {
 	return observer.CurrentBlocks[len(observer.CurrentBlocks)-1]
 }
 
-func NewFakeBlockchainObserverTwo() *BlockchainObserver {
+func NewFakeBlockchainObserver() *BlockchainObserver {
 	return &BlockchainObserver{
 		WasNotified: make(chan bool),
 	}
diff --git a/integration_test/geth_blockchain_test.go b/integration_test/geth_blockchain_test.go
index 199c173f..116527e4 100644
--- a/integration_test/geth_blockchain_test.go
+++ b/integration_test/geth_blockchain_test.go
@@ -26,7 +26,7 @@ var _ = Describe("Reading from the Geth blockchain", func() {
 	var observer *fakes.BlockchainObserver
 
 	BeforeEach(func() {
-		observer = fakes.NewFakeBlockchainObserverTwo()
+		observer = fakes.NewFakeBlockchainObserver()
 		blockchain := geth.NewGethBlockchain(RunTimePath() + "/test_data_dir/geth.ipc")
 		observers := []core.BlockchainObserver{observer}
 		listener = blockchain_listener.NewBlockchainListener(blockchain, observers)
diff --git a/observers/blockchain_db_observer.go b/observers/blockchain_db_observer.go
index 911930ef..504a0367 100644
--- a/observers/blockchain_db_observer.go
+++ b/observers/blockchain_db_observer.go
@@ -3,13 +3,16 @@ package observers
 import (
 	"github.com/8thlight/vulcanizedb/core"
 	"github.com/8thlight/vulcanizedb/repositories"
-	"github.com/jmoiron/sqlx"
 )
 
-type BlockchainDBObserver struct {
-	Db *sqlx.DB
+type BlockchainDbObserver struct {
+	repository repositories.Repository
 }
 
-func (observer BlockchainDBObserver) NotifyBlockAdded(block core.Block) {
-	repositories.NewPostgres(observer.Db).CreateBlock(block)
+func NewBlockchainDbObserver(repository repositories.Repository) BlockchainDbObserver {
+	return BlockchainDbObserver{repository: repository}
+}
+
+func (observer BlockchainDbObserver) NotifyBlockAdded(block core.Block) {
+	observer.repository.CreateBlock(block)
 }
diff --git a/observers/blockchain_db_observer_test.go b/observers/blockchain_db_observer_test.go
index 4bbcec73..0f636a15 100644
--- a/observers/blockchain_db_observer_test.go
+++ b/observers/blockchain_db_observer_test.go
@@ -1,41 +1,23 @@
 package observers_test
 
 import (
-	"runtime"
-
-	"github.com/8thlight/vulcanizedb/config"
 	"github.com/8thlight/vulcanizedb/core"
 	"github.com/8thlight/vulcanizedb/observers"
 	"github.com/8thlight/vulcanizedb/repositories"
-	"github.com/jmoiron/sqlx"
-	_ "github.com/lib/pq"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
 )
 
-var (
-	_, filename, _, _ = runtime.Caller(0)
-)
-
 var _ = Describe("Saving blocks to the database", func() {
 
-	var db *sqlx.DB
-	var err error
+	var repository *repositories.InMemory
 
 	BeforeEach(func() {
-		cfg := config.NewConfig("private")
-		pgConfig := config.DbConnectionString(cfg.Database)
-		db, err = sqlx.Connect("postgres", pgConfig)
-		db.MustExec("DELETE FROM transactions")
-		db.MustExec("DELETE FROM blocks")
-	})
-
-	AfterEach(func() {
-		db.Close()
+		repository = repositories.NewInMemory()
 	})
 
 	It("implements the observer interface", func() {
-		var observer core.BlockchainObserver = observers.BlockchainDBObserver{Db: db}
+		var observer core.BlockchainObserver = observers.NewBlockchainDbObserver(repository)
 		Expect(observer).NotTo(BeNil())
 	})
 
@@ -45,10 +27,9 @@ var _ = Describe("Saving blocks to the database", func() {
 			Transactions: []core.Transaction{{}},
 		}
 
-		observer := observers.BlockchainDBObserver{Db: db}
+		observer := observers.NewBlockchainDbObserver(repository)
 		observer.NotifyBlockAdded(block)
 
-		repository := repositories.NewPostgres(db)
 		savedBlock := repository.FindBlockByNumber(123)
 		Expect(savedBlock).NotTo(BeNil())
 		Expect(len(savedBlock.Transactions)).To(Equal(1))
diff --git a/repositories/repository.go b/repositories/repository.go
new file mode 100644
index 00000000..16aa4055
--- /dev/null
+++ b/repositories/repository.go
@@ -0,0 +1,7 @@
+package repositories
+
+import "github.com/8thlight/vulcanizedb/core"
+
+type Repository interface {
+	CreateBlock(block core.Block)
+}