diff --git a/command/init_test.go b/command/init_test.go
index dee54495d..a0a8c32a0 100644
--- a/command/init_test.go
+++ b/command/init_test.go
@@ -406,6 +406,108 @@ func TestInit_copyBackendDst(t *testing.T) {
 	}
 }
 
+func TestInit_backendReinitWithExtra(t *testing.T) {
+	td := tempDir(t)
+	copy.CopyDir(testFixturePath("init-backend-empty"), td)
+	defer os.RemoveAll(td)
+	defer testChdir(t, td)()
+
+	m := testMetaBackend(t, nil)
+	opts := &BackendOpts{
+		ConfigExtra: map[string]interface{}{"path": "hello"},
+		Init:        true,
+	}
+
+	b, err := m.backendConfig(opts)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ui := new(cli.MockUi)
+	c := &InitCommand{
+		Meta: Meta{
+			ContextOpts: testCtxConfig(testProvider()),
+			Ui:          ui,
+		},
+	}
+
+	args := []string{"-backend-config", "path=hello"}
+	if code := c.Run(args); code != 0 {
+		t.Fatalf("bad: \n%s", ui.ErrorWriter.String())
+	}
+
+	// Read our saved backend config and verify we have our settings
+	state := testStateRead(t, filepath.Join(DefaultDataDir, DefaultStateFilename))
+	if v := state.Backend.Config["path"]; v != "hello" {
+		t.Fatalf("bad: %#v", v)
+	}
+
+	if state.Backend.Hash != b.Hash {
+		t.Fatal("mismatched state and config backend hashes")
+	}
+
+	if state.Backend.Rehash() != b.Rehash() {
+		t.Fatal("mismatched state and config re-hashes")
+	}
+
+	// init again and make sure nothing changes
+	if code := c.Run(args); code != 0 {
+		t.Fatalf("bad: \n%s", ui.ErrorWriter.String())
+	}
+	state = testStateRead(t, filepath.Join(DefaultDataDir, DefaultStateFilename))
+	if v := state.Backend.Config["path"]; v != "hello" {
+		t.Fatalf("bad: %#v", v)
+	}
+
+	if state.Backend.Hash != b.Hash {
+		t.Fatal("mismatched state and config backend hashes")
+	}
+}
+
+// move option from config to -backend-config args
+func TestInit_backendReinitConfigToExtra(t *testing.T) {
+	td := tempDir(t)
+	copy.CopyDir(testFixturePath("init-backend"), td)
+	defer os.RemoveAll(td)
+	defer testChdir(t, td)()
+
+	ui := new(cli.MockUi)
+	c := &InitCommand{
+		Meta: Meta{
+			ContextOpts: testCtxConfig(testProvider()),
+			Ui:          ui,
+		},
+	}
+
+	if code := c.Run([]string{"-input=false"}); code != 0 {
+		t.Fatalf("bad: \n%s", ui.ErrorWriter.String())
+	}
+
+	// Read our saved backend config and verify we have our settings
+	state := testStateRead(t, filepath.Join(DefaultDataDir, DefaultStateFilename))
+	if v := state.Backend.Config["path"]; v != "foo" {
+		t.Fatalf("bad: %#v", v)
+	}
+
+	backendHash := state.Backend.Hash
+
+	// init again but remove the path option from the config
+	cfg := "terraform {\n  backend \"local\" {}\n}\n"
+	if err := ioutil.WriteFile("main.tf", []byte(cfg), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	args := []string{"-input=false", "-backend-config=path=foo"}
+	if code := c.Run(args); code != 0 {
+		t.Fatalf("bad: \n%s", ui.ErrorWriter.String())
+	}
+	state = testStateRead(t, filepath.Join(DefaultDataDir, DefaultStateFilename))
+
+	if state.Backend.Hash == backendHash {
+		t.Fatal("state.Backend.Hash was not updated")
+	}
+}
+
 /*
 func TestInit_remoteState(t *testing.T) {
 	tmp, cwd := testCwd(t)
diff --git a/command/meta_backend.go b/command/meta_backend.go
index b30659dc0..c50214116 100644
--- a/command/meta_backend.go
+++ b/command/meta_backend.go
@@ -415,8 +415,16 @@ func (m *Meta) backendFromConfig(opts *BackendOpts) (backend.Backend, error) {
 	case c != nil && s.Remote.Empty() && !s.Backend.Empty():
 		// If our configuration is the same, then we're just initializing
 		// a previously configured remote backend.
-		if !s.Backend.Empty() && s.Backend.Hash == cHash {
-			return m.backend_C_r_S_unchanged(c, sMgr)
+		if !s.Backend.Empty() {
+			hash := s.Backend.Hash
+			// on init we need an updated hash containing any extra options
+			// that were added after merging.
+			if opts.Init {
+				hash = s.Backend.Rehash()
+			}
+			if hash == cHash {
+				return m.backend_C_r_S_unchanged(c, sMgr)
+			}
 		}
 
 		if !opts.Init {
@@ -451,7 +459,11 @@ func (m *Meta) backendFromConfig(opts *BackendOpts) (backend.Backend, error) {
 	case c != nil && !s.Remote.Empty() && !s.Backend.Empty():
 		// If the hashes are the same, we have a legacy remote state with
 		// an unchanged stored backend state.
-		if s.Backend.Hash == cHash {
+		hash := s.Backend.Hash
+		if opts.Init {
+			hash = s.Backend.Rehash()
+		}
+		if hash == cHash {
 			if !opts.Init {
 				initReason := fmt.Sprintf(
 					"Legacy remote state found with configured backend %q",
@@ -1146,6 +1158,16 @@ func (m *Meta) backend_C_r_S_unchanged(
 	c *config.Backend, sMgr state.State) (backend.Backend, error) {
 	s := sMgr.State()
 
+	// it's possible for a backend to be unchanged, and the config itself to
+	// have changed by moving a paramter from the config to `-backend-config`
+	// In this case we only need to update the Hash.
+	if c != nil && s.Backend.Hash != c.Hash {
+		s.Backend.Hash = c.Hash
+		if err := sMgr.WriteState(s); err != nil {
+			return nil, fmt.Errorf(errBackendWriteSaved, err)
+		}
+	}
+
 	// Create the config. We do this from the backend state since this
 	// has the complete configuration data whereas the config itself
 	// may require input.
diff --git a/command/meta_backend_test.go b/command/meta_backend_test.go
index 8c1fe2d66..143759f98 100644
--- a/command/meta_backend_test.go
+++ b/command/meta_backend_test.go
@@ -3217,6 +3217,110 @@ func TestMetaBackend_planLegacy(t *testing.T) {
 	}
 }
 
+// init a backend using -backend-config options multiple times
+func TestMetaBackend_configureWithExtra(t *testing.T) {
+	// Create a temporary working directory that is empty
+	td := tempDir(t)
+	copy.CopyDir(testFixturePath("init-backend-empty"), td)
+	defer os.RemoveAll(td)
+	defer testChdir(t, td)()
+
+	extras := map[string]interface{}{"path": "hello"}
+	m := testMetaBackend(t, nil)
+	opts := &BackendOpts{
+		ConfigExtra: extras,
+		Init:        true,
+	}
+
+	backendCfg, err := m.backendConfig(opts)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// init the backend
+	_, err = m.Backend(&BackendOpts{
+		ConfigExtra: extras,
+		Init:        true,
+	})
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+
+	// Check the state
+	s := testStateRead(t, filepath.Join(DefaultDataDir, backendlocal.DefaultStateFilename))
+	if s.Backend.Hash != backendCfg.Hash {
+		t.Fatal("mismatched state and config backend hashes")
+	}
+	if s.Backend.Rehash() == s.Backend.Hash {
+		t.Fatal("saved hash should not match actual hash")
+	}
+	if s.Backend.Rehash() != backendCfg.Rehash() {
+		t.Fatal("mismatched state and config re-hashes")
+	}
+
+	// init the backend again with the same options
+	m = testMetaBackend(t, nil)
+	_, err = m.Backend(&BackendOpts{
+		ConfigExtra: extras,
+		Init:        true,
+	})
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+
+	// Check the state
+	s = testStateRead(t, filepath.Join(DefaultDataDir, backendlocal.DefaultStateFilename))
+	if s.Backend.Hash != backendCfg.Hash {
+		t.Fatal("mismatched state and config backend hashes")
+	}
+}
+
+// move options from config to -backend-config
+func TestMetaBackend_configToExtra(t *testing.T) {
+	// Create a temporary working directory that is empty
+	td := tempDir(t)
+	copy.CopyDir(testFixturePath("init-backend"), td)
+	defer os.RemoveAll(td)
+	defer testChdir(t, td)()
+
+	// init the backend
+	m := testMetaBackend(t, nil)
+	_, err := m.Backend(&BackendOpts{
+		Init: true,
+	})
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+
+	// Check the state
+	s := testStateRead(t, filepath.Join(DefaultDataDir, backendlocal.DefaultStateFilename))
+	backendHash := s.Backend.Hash
+
+	// init again but remove the path option from the config
+	cfg := "terraform {\n  backend \"local\" {}\n}\n"
+	if err := ioutil.WriteFile("main.tf", []byte(cfg), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	// init the backend again with the  options
+	extras := map[string]interface{}{"path": "hello"}
+	m = testMetaBackend(t, nil)
+	m.forceInitCopy = true
+	_, err = m.Backend(&BackendOpts{
+		ConfigExtra: extras,
+		Init:        true,
+	})
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+
+	s = testStateRead(t, filepath.Join(DefaultDataDir, backendlocal.DefaultStateFilename))
+
+	if s.Backend.Hash == backendHash {
+		t.Fatal("state.Backend.Hash was not updated")
+	}
+}
+
 func testMetaBackend(t *testing.T, args []string) *Meta {
 	var m Meta
 	m.Ui = new(cli.MockUi)
diff --git a/command/test-fixtures/init-backend-empty/main.tf b/command/test-fixtures/init-backend-empty/main.tf
new file mode 100644
index 000000000..7f62e0e19
--- /dev/null
+++ b/command/test-fixtures/init-backend-empty/main.tf
@@ -0,0 +1,4 @@
+terraform {
+    backend "local" {
+    }
+}
diff --git a/config/config_terraform.go b/config/config_terraform.go
index a547cc798..8535c9648 100644
--- a/config/config_terraform.go
+++ b/config/config_terraform.go
@@ -72,7 +72,7 @@ type Backend struct {
 	Hash uint64
 }
 
-// Hash returns a unique content hash for this backend's configuration
+// Rehash returns a unique content hash for this backend's configuration
 // as a uint64 value.
 func (b *Backend) Rehash() uint64 {
 	// If we have no backend, the value is zero
diff --git a/terraform/state.go b/terraform/state.go
index 4e5aa713f..905ec3dcb 100644
--- a/terraform/state.go
+++ b/terraform/state.go
@@ -801,6 +801,27 @@ func (s *BackendState) Empty() bool {
 	return s == nil || s.Type == ""
 }
 
+// Rehash returns a unique content hash for this backend's configuration
+// as a uint64 value.
+// The Hash stored in the backend state needs to match the config itself, but
+// we need to compare the backend config after it has been combined with all
+// options.
+// This function must match the implementation used by config.Backend.
+func (s *BackendState) Rehash() uint64 {
+	if s == nil {
+		return 0
+	}
+
+	cfg := config.Backend{
+		Type: s.Type,
+		RawConfig: &config.RawConfig{
+			Raw: s.Config,
+		},
+	}
+
+	return cfg.Rehash()
+}
+
 // RemoteState is used to track the information about a remote
 // state store that we push/pull state to.
 type RemoteState struct {