diff --git a/internal/command/init.go b/internal/command/init.go
index 551a4d0b8a..8083b7513d 100644
--- a/internal/command/init.go
+++ b/internal/command/init.go
@@ -44,6 +44,8 @@ func (c *InitCommand) Run(args []string) int {
 	cmdFlags.StringVar(&flagFromModule, "from-module", "", "copy the source of the given module into the directory before init")
 	cmdFlags.BoolVar(&flagGet, "get", true, "")
 	cmdFlags.BoolVar(&c.forceInitCopy, "force-copy", false, "suppress prompts about copying state data")
+	cmdFlags.BoolVar(&c.Meta.stateLock, "lock", true, "lock state")
+	cmdFlags.DurationVar(&c.Meta.stateLockTimeout, "lock-timeout", 0, "lock timeout")
 	cmdFlags.BoolVar(&c.reconfigure, "reconfigure", false, "reconfigure")
 	cmdFlags.BoolVar(&c.migrateState, "migrate-state", false, "migrate state")
 	cmdFlags.BoolVar(&flagUpgrade, "upgrade", false, "")
@@ -932,6 +934,8 @@ func (c *InitCommand) AutocompleteFlags() complete.Flags {
 		"-from-module":    completePredictModuleSource,
 		"-get":            completePredictBoolean,
 		"-input":          completePredictBoolean,
+		"-lock":           completePredictBoolean,
+		"-lock-timeout":   complete.PredictAnything,
 		"-no-color":       complete.PredictNothing,
 		"-plugin-dir":     complete.PredictDirs(""),
 		"-reconfigure":    complete.PredictNothing,
@@ -959,7 +963,8 @@ Usage: terraform [global options] init [options]
 
 Options:
 
-  -backend=true           Configure the backend for this configuration.
+  -backend=false          Disable backend initialization for this configuration
+                          and use the previously initialized backend instead.
 
   -backend-config=path    This can be either a path to an HCL file with key/value
                           assignments (same format as terraform.tfvars) or a
@@ -975,10 +980,17 @@ Options:
   -from-module=SOURCE     Copy the contents of the given module into the target
                           directory before initialization.
 
-  -get=true               Download any modules for this configuration.
+  -get=false              Disable downloading modules for this configuration.
 
-  -input=true             Ask for input if necessary. If false, will error if
-                          input was required.
+  -input=false            Disable prompting for missing backend configuration
+                          values. This will result in an error if the backend
+                          configuration is not fully specified.
+
+  -lock=false             Don't hold a state lock during backend migration.
+                          This is dangerous if others might concurrently run
+                          commands against the same workspace.
+
+  -lock-timeout=0s        Duration to retry a state lock.
 
   -no-color               If specified, output won't contain any color.
 
@@ -993,9 +1005,10 @@ Options:
   -migrate-state          Reconfigure the backend, and attempt to migrate any
                           existing state.
 
-  -upgrade=false          If installing modules (-get) or plugins, ignore
-                          previously-downloaded objects and install the
-                          latest version allowed within configured constraints.
+  -upgrade                Install the latest module and provider versions
+                          allowed within configured constraints, overriding the
+                          default behavior of selecting exactly the version
+                          recorded in the dependency lockfile.
 
   -lockfile=MODE          Set a dependency lockfile mode.
                           Currently only "readonly" is valid.
diff --git a/internal/command/init_test.go b/internal/command/init_test.go
index 74d4b0f64d..56bc1f9116 100644
--- a/internal/command/init_test.go
+++ b/internal/command/init_test.go
@@ -562,6 +562,60 @@ func TestInit_backendConfigFileChange(t *testing.T) {
 	}
 }
 
+func TestInit_backendMigrateWhileLocked(t *testing.T) {
+	// Create a temporary working directory that is empty
+	td := tempDir(t)
+	testCopyDir(t, testFixturePath("init-backend-migrate-while-locked"), td)
+	defer os.RemoveAll(td)
+	defer testChdir(t, td)()
+
+	providerSource, close := newMockProviderSource(t, map[string][]string{
+		"hashicorp/test": {"1.2.3"},
+	})
+	defer close()
+
+	ui := new(cli.MockUi)
+	view, _ := testView(t)
+	c := &InitCommand{
+		Meta: Meta{
+			testingOverrides: metaOverridesForProvider(testProvider()),
+			ProviderSource:   providerSource,
+			Ui:               ui,
+			View:             view,
+		},
+	}
+
+	// Create some state, so the backend has something to migrate from
+	f, err := os.Create("local-state.tfstate")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+	err = writeStateForTesting(testState(), f)
+	f.Close()
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Lock the source state
+	unlock, err := testLockState(testDataDir, "local-state.tfstate")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer unlock()
+
+	// Attempt to migrate
+	args := []string{"-backend-config", "input.config", "-migrate-state", "-force-copy"}
+	if code := c.Run(args); code == 0 {
+		t.Fatalf("expected nonzero exit code: %s", ui.OutputWriter.String())
+	}
+
+	// Disabling locking should work
+	args = []string{"-backend-config", "input.config", "-migrate-state", "-force-copy", "-lock=false"}
+	if code := c.Run(args); code != 0 {
+		t.Fatalf("expected zero exit code, got %d: %s", code, ui.ErrorWriter.String())
+	}
+}
+
 func TestInit_backendConfigKV(t *testing.T) {
 	// Create a temporary working directory that is empty
 	td := tempDir(t)
diff --git a/internal/command/testdata/init-backend-migrate-while-locked/.terraform/terraform.tfstate b/internal/command/testdata/init-backend-migrate-while-locked/.terraform/terraform.tfstate
new file mode 100644
index 0000000000..073bd7a822
--- /dev/null
+++ b/internal/command/testdata/init-backend-migrate-while-locked/.terraform/terraform.tfstate
@@ -0,0 +1,22 @@
+{
+    "version": 3,
+    "serial": 0,
+    "lineage": "666f9301-7e65-4b19-ae23-71184bb19b03",
+    "backend": {
+        "type": "local",
+        "config": {
+            "path": "local-state.tfstate"
+        },
+        "hash": 9073424445967744180
+    },
+    "modules": [
+        {
+            "path": [
+                "root"
+            ],
+            "outputs": {},
+            "resources": {},
+            "depends_on": []
+        }
+    ]
+}
diff --git a/internal/command/testdata/init-backend-migrate-while-locked/input.config b/internal/command/testdata/init-backend-migrate-while-locked/input.config
new file mode 100644
index 0000000000..6cd14f4a3d
--- /dev/null
+++ b/internal/command/testdata/init-backend-migrate-while-locked/input.config
@@ -0,0 +1 @@
+path = "hello"
diff --git a/internal/command/testdata/init-backend-migrate-while-locked/main.tf b/internal/command/testdata/init-backend-migrate-while-locked/main.tf
new file mode 100644
index 0000000000..bea8e789f8
--- /dev/null
+++ b/internal/command/testdata/init-backend-migrate-while-locked/main.tf
@@ -0,0 +1,5 @@
+terraform {
+  backend "local" {
+    path = "local-state.tfstate"
+  }
+}