diff --git a/Code/Mantid/Framework/Geometry/src/Crystal/PointGroup.cpp b/Code/Mantid/Framework/Geometry/src/Crystal/PointGroup.cpp
index 81180588d552b1ea2d2bde8e2b6767f9b005540c..dd00f62d5002460b2bcdc0e7a94c0f7afa193b76 100644
--- a/Code/Mantid/Framework/Geometry/src/Crystal/PointGroup.cpp
+++ b/Code/Mantid/Framework/Geometry/src/Crystal/PointGroup.cpp
@@ -156,7 +156,7 @@ PointGroup::CrystalSystem PointGroup::getCrystalSystemFromGroup() const {
     return Trigonal;
   }
 
-  if (symbolMap["4"].size() == 1) {
+  if (symbolMap["4"].size() == 1 || symbolMap["-4"].size() == 1) {
     return Tetragonal;
   }