diff --git a/consul/fsm.go b/consul/fsm.go
index 9810a289be..654c5f16c2 100644
--- a/consul/fsm.go
+++ b/consul/fsm.go
@@ -85,29 +85,11 @@ func (c *consulFSM) decodeRegister(buf []byte, index uint64) interface{} {
 }
 
 func (c *consulFSM) applyRegister(req *structs.RegisterRequest, index uint64) interface{} {
-	// Ensure the node
-	node := structs.Node{req.Node, req.Address}
-	if err := c.state.EnsureNode(index, node); err != nil {
-		c.logger.Printf("[INFO] consul.fsm: EnsureNode failed: %v", err)
+	// Apply all updates in a single transaction
+	if err := c.state.EnsureRegistration(index, req); err != nil {
+		c.logger.Printf("[INFO] consul.fsm: EnsureRegistration failed: %v", err)
 		return err
 	}
-
-	// Ensure the service if provided
-	if req.Service != nil {
-		if err := c.state.EnsureService(index, req.Node, req.Service); err != nil {
-			c.logger.Printf("[INFO] consul.fsm: EnsureService failed: %v", err)
-			return err
-		}
-	}
-
-	// Ensure the check if provided
-	if req.Check != nil {
-		if err := c.state.EnsureCheck(index, req.Check); err != nil {
-			c.logger.Printf("[INFO] consul.fsm: EnsureCheck failed: %v", err)
-			return err
-		}
-	}
-
 	return nil
 }
 
diff --git a/consul/issue_test.go b/consul/issue_test.go
new file mode 100644
index 0000000000..6bcd66e8a3
--- /dev/null
+++ b/consul/issue_test.go
@@ -0,0 +1,77 @@
+package consul
+
+import (
+	"os"
+	"reflect"
+	"testing"
+
+	"github.com/hashicorp/consul/consul/structs"
+)
+
+// Testing for GH-300 and GH-279
+func TestHealthCheckRace(t *testing.T) {
+	fsm, err := NewFSM(os.Stderr)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	defer fsm.Close()
+	state := fsm.State()
+
+	req := structs.RegisterRequest{
+		Datacenter: "dc1",
+		Node:       "foo",
+		Address:    "127.0.0.1",
+		Service: &structs.NodeService{
+			ID:      "db",
+			Service: "db",
+		},
+		Check: &structs.HealthCheck{
+			Node:      "foo",
+			CheckID:   "db",
+			Name:      "db connectivity",
+			Status:    structs.HealthPassing,
+			ServiceID: "db",
+		},
+	}
+	buf, err := structs.Encode(structs.RegisterRequestType, req)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	log := makeLog(buf)
+	log.Index = 10
+	resp := fsm.Apply(log)
+	if resp != nil {
+		t.Fatalf("resp: %v", resp)
+	}
+
+	// Verify the index
+	idx, out1 := state.CheckServiceNodes("db")
+	if idx != 10 {
+		t.Fatalf("Bad index")
+	}
+
+	// Update the check state
+	req.Check.Status = structs.HealthCritical
+	buf, err = structs.Encode(structs.RegisterRequestType, req)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	log = makeLog(buf)
+	log.Index = 20
+	resp = fsm.Apply(log)
+	if resp != nil {
+		t.Fatalf("resp: %v", resp)
+	}
+
+	// Verify the index changed
+	idx, out2 := state.CheckServiceNodes("db")
+	if idx != 20 {
+		t.Fatalf("Bad index")
+	}
+
+	if reflect.DeepEqual(out1, out2) {
+		t.Fatalf("match: %#v %#v", *out1[0].Checks[0], *out2[0].Checks[0])
+	}
+}
diff --git a/consul/state_store.go b/consul/state_store.go
index 80870ac5a8..420d9bc6ac 100644
--- a/consul/state_store.go
+++ b/consul/state_store.go
@@ -375,6 +375,39 @@ func (s *StateStore) QueryTables(q string) MDBTables {
 	return s.queryTables[q]
 }
 
+// EnsureRegistration is used to make sure a node, service, and check registration
+// is performed within a single transaction to avoid race conditions on state updates.
+func (s *StateStore) EnsureRegistration(index uint64, req *structs.RegisterRequest) error {
+	tx, err := s.tables.StartTxn(false)
+	if err != nil {
+		panic(fmt.Errorf("Failed to start txn: %v", err))
+	}
+	defer tx.Abort()
+
+	// Ensure the node
+	node := structs.Node{req.Node, req.Address}
+	if err := s.ensureNodeTxn(index, node, tx); err != nil {
+		return err
+	}
+
+	// Ensure the service if provided
+	if req.Service != nil {
+		if err := s.ensureServiceTxn(index, req.Node, req.Service, tx); err != nil {
+			return err
+		}
+	}
+
+	// Ensure the check if provided
+	if req.Check != nil {
+		if err := s.ensureCheckTxn(index, req.Check, tx); err != nil {
+			return err
+		}
+	}
+
+	// Commit as one unit
+	return tx.Commit()
+}
+
 // EnsureNode is used to ensure a given node exists, with the provided address
 func (s *StateStore) EnsureNode(index uint64, node structs.Node) error {
 	tx, err := s.nodeTable.StartTxn(false, nil)
diff --git a/consul/state_store_test.go b/consul/state_store_test.go
index f0cdae90f3..2c2a0fd012 100644
--- a/consul/state_store_test.go
+++ b/consul/state_store_test.go
@@ -13,6 +13,57 @@ func testStateStore() (*StateStore, error) {
 	return NewStateStore(os.Stderr)
 }
 
+func TestEnsureRegistration(t *testing.T) {
+	store, err := testStateStore()
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	defer store.Close()
+
+	reg := &structs.RegisterRequest{
+		Node:    "foo",
+		Address: "127.0.0.1",
+		Service: &structs.NodeService{"api", "api", nil, 5000},
+		Check: &structs.HealthCheck{
+			Node:      "foo",
+			CheckID:   "api",
+			Name:      "Can connect",
+			Status:    structs.HealthPassing,
+			ServiceID: "api",
+		},
+	}
+
+	if err := store.EnsureRegistration(13, reg); err != nil {
+		t.Fatalf("err: %v")
+	}
+
+	idx, found, addr := store.GetNode("foo")
+	if idx != 13 || !found || addr != "127.0.0.1" {
+		t.Fatalf("Bad: %v %v %v", idx, found, addr)
+	}
+
+	idx, services := store.NodeServices("foo")
+	if idx != 13 {
+		t.Fatalf("bad: %v", idx)
+	}
+
+	entry, ok := services.Services["api"]
+	if !ok {
+		t.Fatalf("missing api: %#v", services)
+	}
+	if entry.Tags != nil || entry.Port != 5000 {
+		t.Fatalf("Bad entry: %#v", entry)
+	}
+
+	idx, checks := store.NodeChecks("foo")
+	if idx != 13 {
+		t.Fatalf("bad: %v", idx)
+	}
+	if len(checks) != 1 {
+		t.Fatalf("check: %#v", checks)
+	}
+}
+
 func TestEnsureNode(t *testing.T) {
 	store, err := testStateStore()
 	if err != nil {