diff --git a/image_analysis/RotationIndexer.cpp b/image_analysis/RotationIndexer.cpp
index 9d860096..8e1264c7 100644
--- a/image_analysis/RotationIndexer.cpp
+++ b/image_analysis/RotationIndexer.cpp
@@ -130,7 +130,7 @@ std::optional<CrystalLattice> RotationIndexer::ProcessImage(int64_t image, const
     }
 
     if (indexed_lattice)
-        return indexed_lattice->Multiply(rot);
+        return indexed_lattice->Multiply(rot.transpose());
     return {};
 }