diff --git a/journal.go b/journal.go
index 3ce4bd1..dfebbe0 100644
--- a/journal.go
+++ b/journal.go
@@ -266,7 +266,7 @@ func fluxTime(value string) (time.Time, error) {
 	if value == "" {
 		return time.Time{}, core.E("store.fluxTime", "range value is empty", nil)
 	}
-	value = firstString(core.Split(value, ","))
+	value = firstOrEmptyString(core.Split(value, ","))
 	value = core.Trim(value)
 	if core.HasPrefix(value, "time(v:") && core.HasSuffix(value, ")") {
 		value = core.Trim(core.TrimSuffix(core.TrimPrefix(value, "time(v:"), ")"))
diff --git a/scope.go b/scope.go
index f7d0b89..08e582e 100644
--- a/scope.go
+++ b/scope.go
@@ -172,13 +172,13 @@ func (scopedStore *ScopedStore) Count(group string) (int, error) {
 // Usage example: `keyCount, err := scopedStore.CountAll("config")`
 // Usage example: `keyCount, err := scopedStore.CountAll()`
 func (scopedStore *ScopedStore) CountAll(groupPrefix ...string) (int, error) {
-	return scopedStore.store.CountAll(scopedStore.namespacedGroup(firstString(groupPrefix)))
+	return scopedStore.store.CountAll(scopedStore.namespacedGroup(firstOrEmptyString(groupPrefix)))
 }
 
 // Usage example: `groupNames, err := scopedStore.Groups("config")`
 // Usage example: `groupNames, err := scopedStore.Groups()`
 func (scopedStore *ScopedStore) Groups(groupPrefix ...string) ([]string, error) {
-	groupNames, err := scopedStore.store.Groups(scopedStore.namespacedGroup(firstString(groupPrefix)))
+	groupNames, err := scopedStore.store.Groups(scopedStore.namespacedGroup(firstOrEmptyString(groupPrefix)))
 	if err != nil {
 		return nil, err
 	}
@@ -193,7 +193,7 @@ func (scopedStore *ScopedStore) Groups(groupPrefix ...string) ([]string, error)
 func (scopedStore *ScopedStore) GroupsSeq(groupPrefix ...string) iter.Seq2[string, error] {
 	return func(yield func(string, error) bool) {
 		namespacePrefix := scopedStore.namespacePrefix()
-		for groupName, err := range scopedStore.store.GroupsSeq(scopedStore.namespacedGroup(firstString(groupPrefix))) {
+		for groupName, err := range scopedStore.store.GroupsSeq(scopedStore.namespacedGroup(firstOrEmptyString(groupPrefix))) {
 			if err != nil {
 				if !yield("", err) {
 					return
diff --git a/store.go b/store.go
index f71416f..347951c 100644
--- a/store.go
+++ b/store.go
@@ -372,7 +372,7 @@ func (storeInstance *Store) Groups(groupPrefix ...string) ([]string, error) {
 // Usage example: `for tenantGroupName, err := range storeInstance.GroupsSeq("tenant-a:") { if err != nil { break }; fmt.Println(tenantGroupName) }`
 // Usage example: `for groupName, err := range storeInstance.GroupsSeq() { if err != nil { break }; fmt.Println(groupName) }`
 func (storeInstance *Store) GroupsSeq(groupPrefix ...string) iter.Seq2[string, error] {
-	actualGroupPrefix := firstString(groupPrefix)
+	actualGroupPrefix := firstOrEmptyString(groupPrefix)
 	return func(yield func(string, error) bool) {
 		var rows *sql.Rows
 		var err error
@@ -412,7 +412,7 @@ func (storeInstance *Store) GroupsSeq(groupPrefix ...string) iter.Seq2[string, e
 	}
 }
 
-func firstString(values []string) string {
+func firstOrEmptyString(values []string) string {
 	if len(values) == 0 {
 		return ""
 	}