diff --git a/src/apps/EDGE3D.hpp b/src/apps/EDGE3D.hpp
index 2d39ecf30..81ab21ba5 100644
--- a/src/apps/EDGE3D.hpp
+++ b/src/apps/EDGE3D.hpp
@@ -534,6 +534,19 @@ RAJA_INLINE void symmetric_edge_MpSmatrix(
       }
     }
   }
+
+  // write back to matrix
+  rajaperf::Int_type offset = 0;
+  for (rajaperf::Int_type p = 0; p < M; p++) {
+
+    matrix[p][p] = symmetric_matrix[offset];
+    for (rajaperf::Int_type m = 1; m < (M-p); m++) {
+      auto x = symmetric_matrix[offset + m];
+      matrix[p][m] = x;
+      matrix[m][p] = x;
+    }
+    offset += (M-p);
+  }
 }
 
 #define EDGE3D_DATA_SETUP \