diff --git a/test/pdegen/psb_d_pde2d.F90 b/test/pdegen/psb_d_pde2d.F90
index 07532098..183b8d16 100644
--- a/test/pdegen/psb_d_pde2d.F90
+++ b/test/pdegen/psb_d_pde2d.F90
@@ -230,7 +230,7 @@ contains
       f_ => d_null_func_2d
     end if
 
-    deltah   = done/(idim+2)
+    deltah   = done/(idim+1)
     sqdeltah = deltah*deltah
     deltah2  = (2*done)* deltah
 
diff --git a/test/pdegen/psb_d_pde3d.F90 b/test/pdegen/psb_d_pde3d.F90
index 57c5905d..b0e69256 100644
--- a/test/pdegen/psb_d_pde3d.F90
+++ b/test/pdegen/psb_d_pde3d.F90
@@ -246,7 +246,7 @@ contains
       f_ => d_null_func_3d
     end if
 
-    deltah   = done/(idim+2)
+    deltah   = done/(idim+1)
     sqdeltah = deltah*deltah
     deltah2  = (2*done)* deltah
 
diff --git a/test/pdegen/psb_s_pde2d.F90 b/test/pdegen/psb_s_pde2d.F90
index 43ad13a5..a4d724ca 100644
--- a/test/pdegen/psb_s_pde2d.F90
+++ b/test/pdegen/psb_s_pde2d.F90
@@ -230,7 +230,7 @@ contains
       f_ => s_null_func_2d
     end if
 
-    deltah   = sone/(idim+2)
+    deltah   = sone/(idim+1)
     sqdeltah = deltah*deltah
     deltah2  = (2*sone)* deltah
 
diff --git a/test/pdegen/psb_s_pde3d.F90 b/test/pdegen/psb_s_pde3d.F90
index 86683196..87e631c7 100644
--- a/test/pdegen/psb_s_pde3d.F90
+++ b/test/pdegen/psb_s_pde3d.F90
@@ -246,7 +246,7 @@ contains
       f_ => s_null_func_3d
     end if
 
-    deltah   = sone/(idim+2)
+    deltah   = sone/(idim+1)
     sqdeltah = deltah*deltah
     deltah2  = (2*sone)* deltah