diff --git a/internal/backend/local/backend_local_test.go b/internal/backend/local/backend_local_test.go
index 2e84d01f6a..83c0c17cbd 100644
--- a/internal/backend/local/backend_local_test.go
+++ b/internal/backend/local/backend_local_test.go
@@ -161,8 +161,9 @@ func TestLocalRun_stalePlan(t *testing.T) {
 		UIMode:  plans.NormalMode,
 		Changes: plans.NewChangesSrc(),
 		Backend: &plans.Backend{
-			Type:   "local",
-			Config: backendConfigRaw,
+			Type:      "local",
+			Config:    backendConfigRaw,
+			Workspace: "default",
 		},
 		PrevRunState: states.NewState(),
 		PriorState:   states.NewState(),
diff --git a/internal/backend/local/backend_plan_test.go b/internal/backend/local/backend_plan_test.go
index 1f6a10f250..f7ecb0f6f4 100644
--- a/internal/backend/local/backend_plan_test.go
+++ b/internal/backend/local/backend_plan_test.go
@@ -207,8 +207,9 @@ func TestLocal_planOutputsChanged(t *testing.T) {
 	}
 	op.PlanOutBackend = &plans.Backend{
 		// Just a placeholder so that we can generate a valid plan file.
-		Type:   "local",
-		Config: cfgRaw,
+		Type:      "local",
+		Config:    cfgRaw,
+		Workspace: "default",
 	}
 	run, err := b.Operation(context.Background(), op)
 	if err != nil {
@@ -263,8 +264,9 @@ func TestLocal_planModuleOutputsChanged(t *testing.T) {
 		t.Fatal(err)
 	}
 	op.PlanOutBackend = &plans.Backend{
-		Type:   "local",
-		Config: cfgRaw,
+		Type:      "local",
+		Config:    cfgRaw,
+		Workspace: "default",
 	}
 	run, err := b.Operation(context.Background(), op)
 	if err != nil {
@@ -305,8 +307,9 @@ func TestLocal_planTainted(t *testing.T) {
 	}
 	op.PlanOutBackend = &plans.Backend{
 		// Just a placeholder so that we can generate a valid plan file.
-		Type:   "local",
-		Config: cfgRaw,
+		Type:      "local",
+		Config:    cfgRaw,
+		Workspace: "default",
 	}
 	run, err := b.Operation(context.Background(), op)
 	if err != nil {
@@ -384,8 +387,9 @@ func TestLocal_planDeposedOnly(t *testing.T) {
 	}
 	op.PlanOutBackend = &plans.Backend{
 		// Just a placeholder so that we can generate a valid plan file.
-		Type:   "local",
-		Config: cfgRaw,
+		Type:      "local",
+		Config:    cfgRaw,
+		Workspace: "default",
 	}
 	run, err := b.Operation(context.Background(), op)
 	if err != nil {
@@ -475,8 +479,9 @@ func TestLocal_planTainted_createBeforeDestroy(t *testing.T) {
 	}
 	op.PlanOutBackend = &plans.Backend{
 		// Just a placeholder so that we can generate a valid plan file.
-		Type:   "local",
-		Config: cfgRaw,
+		Type:      "local",
+		Config:    cfgRaw,
+		Workspace: "default",
 	}
 	run, err := b.Operation(context.Background(), op)
 	if err != nil {
@@ -566,8 +571,9 @@ func TestLocal_planDestroy(t *testing.T) {
 	}
 	op.PlanOutBackend = &plans.Backend{
 		// Just a placeholder so that we can generate a valid plan file.
-		Type:   "local",
-		Config: cfgRaw,
+		Type:      "local",
+		Config:    cfgRaw,
+		Workspace: "default",
 	}
 
 	run, err := b.Operation(context.Background(), op)
@@ -618,8 +624,9 @@ func TestLocal_planDestroy_withDataSources(t *testing.T) {
 	}
 	op.PlanOutBackend = &plans.Backend{
 		// Just a placeholder so that we can generate a valid plan file.
-		Type:   "local",
-		Config: cfgRaw,
+		Type:      "local",
+		Config:    cfgRaw,
+		Workspace: "default",
 	}
 
 	run, err := b.Operation(context.Background(), op)
@@ -690,8 +697,9 @@ func TestLocal_planOutPathNoChange(t *testing.T) {
 	}
 	op.PlanOutBackend = &plans.Backend{
 		// Just a placeholder so that we can generate a valid plan file.
-		Type:   "local",
-		Config: cfgRaw,
+		Type:      "local",
+		Config:    cfgRaw,
+		Workspace: "default",
 	}
 	op.PlanRefresh = true
 
diff --git a/internal/command/apply_test.go b/internal/command/apply_test.go
index 2e7e22a850..b3c91dbef4 100644
--- a/internal/command/apply_test.go
+++ b/internal/command/apply_test.go
@@ -1087,8 +1087,9 @@ func TestApply_plan_remoteState(t *testing.T) {
 	}
 	planPath := testPlanFile(t, snap, state, &plans.Plan{
 		Backend: &plans.Backend{
-			Type:   "http",
-			Config: backendConfigRaw,
+			Type:      "http",
+			Config:    backendConfigRaw,
+			Workspace: "default",
 		},
 		Changes: plans.NewChangesSrc(),
 	})
diff --git a/internal/command/graph_test.go b/internal/command/graph_test.go
index dc98f74c71..8193614329 100644
--- a/internal/command/graph_test.go
+++ b/internal/command/graph_test.go
@@ -329,8 +329,9 @@ func TestGraph_applyPhaseSavedPlan(t *testing.T) {
 		// Doesn't actually matter since we aren't going to activate the backend
 		// for this command anyway, but we need something here for the plan
 		// file writer to succeed.
-		Type:   "placeholder",
-		Config: emptyObj,
+		Type:      "placeholder",
+		Config:    emptyObj,
+		Workspace: "default",
 	}
 	_, configSnap := testModuleWithSnapshot(t, "graph")