diff --git a/vault/activity_log.go b/vault/activity_log.go
index d206985cc0..f52519a61b 100644
--- a/vault/activity_log.go
+++ b/vault/activity_log.go
@@ -1571,16 +1571,16 @@ func (a *ActivityLog) receivedFragment(fragment *activity.LogFragment) {
 }
 
 type ResponseCounts struct {
-	DistinctEntities int `json:"distinct_entities"`
-	EntityClients    int `json:"entity_clients"`
-	NonEntityTokens  int `json:"non_entity_tokens"`
-	NonEntityClients int `json:"non_entity_clients"`
+	DistinctEntities int `json:"distinct_entities" mapstructure:"distinct_entities"`
+	EntityClients    int `json:"entity_clients" mapstructure:"entity_clients"`
+	NonEntityTokens  int `json:"non_entity_tokens" mapstructure:"non_entity_tokens"`
+	NonEntityClients int `json:"non_entity_clients" mapstructure:"non_entity_clients"`
 	Clients          int `json:"clients"`
 }
 
 type ResponseNamespace struct {
-	NamespaceID   string           `json:"namespace_id"`
-	NamespacePath string           `json:"namespace_path"`
+	NamespaceID   string           `json:"namespace_id" mapstructure:"namespace_id"`
+	NamespacePath string           `json:"namespace_path" mapstructure:"namespace_path"`
 	Counts        ResponseCounts   `json:"counts"`
 	Mounts        []*ResponseMount `json:"mounts"`
 }
@@ -1598,7 +1598,7 @@ type ResponseNewClients struct {
 }
 
 type ResponseMount struct {
-	MountPath string          `json:"mount_path"`
+	MountPath string          `json:"mount_path" mapstructure:"mount_path"`
 	Counts    *ResponseCounts `json:"counts"`
 }
 
diff --git a/vault/logical_system_activity_write_testonly.go b/vault/logical_system_activity_write_testonly.go
index e890d87d46..62f7366887 100644
--- a/vault/logical_system_activity_write_testonly.go
+++ b/vault/logical_system_activity_write_testonly.go
@@ -9,6 +9,7 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"strings"
 	"sync"
 	"time"
 
@@ -226,6 +227,7 @@ func (m *multipleMonthsActivityClients) processMonth(ctx context.Context, core *
 	m.months[month.GetMonthsAgo()].generationParameters = month
 	add := func(c []*generation.Client, segmentIndex *int) error {
 		for _, clients := range c {
+			mountAccessor := defaultMountAccessorRootNS
 
 			if clients.Namespace == "" {
 				clients.Namespace = namespace.RootNamespaceID
@@ -234,34 +236,41 @@ func (m *multipleMonthsActivityClients) processMonth(ctx context.Context, core *
 				clients.ClientType = entityActivityType
 			}
 
-			// verify that the namespace exists
-			ns, err := core.NamespaceByID(ctx, clients.Namespace)
-			if err != nil {
-				return err
+			if clients.Namespace != namespace.RootNamespaceID && !strings.HasSuffix(clients.Namespace, "/") {
+				clients.Namespace += "/"
 			}
+			// verify that the namespace exists
+			ns := core.namespaceByPath(clients.Namespace)
+			if ns.ID == namespace.RootNamespaceID && clients.Namespace != namespace.RootNamespaceID {
+				return fmt.Errorf("unable to find namespace %s", clients.Namespace)
+			}
+			clients.Namespace = ns.ID
 
 			// verify that the mount exists
 			if clients.Mount != "" {
+				if !strings.HasSuffix(clients.Mount, "/") {
+					clients.Mount += "/"
+				}
 				nctx := namespace.ContextWithNamespace(ctx, ns)
 				mountEntry := core.router.MatchingMountEntry(nctx, clients.Mount)
 				if mountEntry == nil {
-					return fmt.Errorf("unable to find matching mount in namespace %s", clients.Namespace)
+					return fmt.Errorf("unable to find matching mount in namespace %s", ns.Path)
 				}
+				mountAccessor = mountEntry.Accessor
 			}
 
-			mountAccessor := defaultMountAccessorRootNS
 			if clients.Namespace != namespace.RootNamespaceID && clients.Mount == "" {
 				// if we're not using the root namespace, find a mount on the namespace that we are using
 				found := false
 				for _, mount := range mounts {
-					if mount.NamespaceID == clients.Namespace {
+					if mount.NamespaceID == ns.ID {
 						mountAccessor = mount.Accessor
 						found = true
 						break
 					}
 				}
 				if !found {
-					return fmt.Errorf("unable to find matching mount in namespace %s", clients.Namespace)
+					return fmt.Errorf("unable to find matching mount in namespace %s", ns.Path)
 				}
 			}
 
diff --git a/vault/logical_system_activity_write_testonly_test.go b/vault/logical_system_activity_write_testonly_test.go
index 3747016419..fd2ce2b38d 100644
--- a/vault/logical_system_activity_write_testonly_test.go
+++ b/vault/logical_system_activity_write_testonly_test.go
@@ -215,6 +215,16 @@ func Test_multipleMonthsActivityClients_processMonth(t *testing.T) {
 			},
 			numMonths: 1,
 		},
+		{
+			name: "mount missing slash",
+			clients: &generation.Data{
+				Clients: &generation.Data_All{All: &generation.Clients{Clients: []*generation.Client{{
+					Namespace: namespace.RootNamespaceID,
+					Mount:     "identity",
+				}}}},
+			},
+			numMonths: 1,
+		},
 		{
 			name: "specified namespace exists, mount empty",
 			clients: &generation.Data{