diff --git a/pkg/og/flameql/flameql.go b/pkg/og/flameql/flameql.go
index 94eb15c1af..bca663025e 100644
--- a/pkg/og/flameql/flameql.go
+++ b/pkg/og/flameql/flameql.go
@@ -97,7 +97,7 @@ func ValidateAppName(n string) error {
 }
 
 func IsTagKeyRuneAllowed(r rune) bool {
-	return (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || (r >= '0' && r <= '9') || r == '_'
+	return (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || (r >= '0' && r <= '9') || r == '_' || r == '.'
 }
 
 func IsAppNameRuneAllowed(r rune) bool {
diff --git a/pkg/og/flameql/flameql_test.go b/pkg/og/flameql/flameql_test.go
index 15219eebae..f6baea64e1 100644
--- a/pkg/og/flameql/flameql_test.go
+++ b/pkg/og/flameql/flameql_test.go
@@ -43,6 +43,7 @@ var _ = Describe("ValidateTagKey", func() {
 
 		testCases := []testCase{
 			{"foo_BAR_12_baz_qux", nil},
+			{"service.namespace", nil},
 
 			{ReservedTagKeyName, ErrTagKeyReserved},
 			{"", ErrTagKeyIsRequired},