diff --git a/components/style/logical_geometry.rs b/components/style/logical_geometry.rs
index 38ffb25a740..c1e01216d19 100644
--- a/components/style/logical_geometry.rs
+++ b/components/style/logical_geometry.rs
@@ -140,6 +140,8 @@ impl WritingMode {
                         TextOrientation::Mixed => {},
                         TextOrientation::Upright => {
                             flags.insert(WritingMode::UPRIGHT);
+                            flags.remove(WritingMode::RTL);
+                            flags.remove(WritingMode::INLINE_REVERSED);
                         },
                         TextOrientation::Sideways => {
                             flags.insert(WritingMode::SIDEWAYS);