diff --git a/src/input_cp2k_global.F b/src/input_cp2k_global.F
index cb20ddab88..a49ccea395 100644
--- a/src/input_cp2k_global.F
+++ b/src/input_cp2k_global.F
@@ -754,7 +754,7 @@ CONTAINS
                           default_i_val=GRID_BACKEND_AUTO, &
                           enum_i_vals=(/GRID_BACKEND_AUTO, GRID_BACKEND_REF, GRID_BACKEND_CPU, &
                                         GRID_BACKEND_DGEMM, GRID_BACKEND_GPU, GRID_BACKEND_HIP/), &
-                          enum_c_vals=s2a("AUTO", "REF", "CPU", "DGEMM", "GPU", "HIP"), &
+                          enum_c_vals=s2a("AUTO", "REFERENCE", "CPU", "DGEMM", "GPU", "HIP"), &
                           enum_desc=s2a("Let the grid library pick the backend automatically", &
                                         "Reference backend implementation", &
                                         "Optimized CPU backend", &
diff --git a/tests/QS/regtest-gpw-1/Ar-3.inp b/tests/QS/regtest-gpw-1/Ar-3.inp
index 46bc66c9e4..4525372b8c 100644
--- a/tests/QS/regtest-gpw-1/Ar-3.inp
+++ b/tests/QS/regtest-gpw-1/Ar-3.inp
@@ -41,6 +41,6 @@
 &GLOBAL
   PRINT_LEVEL MEDIUM
   &GRID
-    BACKEND REF ! basis is too large for GPU backend
+    BACKEND CPU ! basis is too large for GPU backend
   &END GRID
 &END GLOBAL
diff --git a/tests/QS/regtest-grid/simple_non-ortho_grid_ref.inp b/tests/QS/regtest-grid/simple_non-ortho_grid_ref.inp
index 85701e84f7..7caa70b295 100644
--- a/tests/QS/regtest-grid/simple_non-ortho_grid_ref.inp
+++ b/tests/QS/regtest-grid/simple_non-ortho_grid_ref.inp
@@ -63,7 +63,7 @@ C    1.22800000 -0.70898613  5.02200000
 &END FORCE_EVAL
 &GLOBAL
   &GRID
-    BACKEND REF
+    BACKEND REFERENCE
   &END GRID
   PROJECT simple_non-ortho_grid_ref
   PRINT_LEVEL MEDIUM
diff --git a/tests/QS/regtest-grid/simple_ortho_grid_ref.inp b/tests/QS/regtest-grid/simple_ortho_grid_ref.inp
index 5cd25ee59b..7c01cd8649 100644
--- a/tests/QS/regtest-grid/simple_ortho_grid_ref.inp
+++ b/tests/QS/regtest-grid/simple_ortho_grid_ref.inp
@@ -51,7 +51,7 @@
 &END FORCE_EVAL
 &GLOBAL
   &GRID
-    BACKEND REF
+    BACKEND REFERENCE
   &END GRID
   PROJECT simple_ortho_grid_ref
   PRINT_LEVEL MEDIUM