diff --git a/test/pdegen/psb_d_pde2d.F90 b/test/pdegen/psb_d_pde2d.F90
index 7da7439b..07532098 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+1)
+    deltah   = done/(idim+2)
     sqdeltah = deltah*deltah
     deltah2  = (2*done)* deltah
 
@@ -467,8 +467,8 @@ contains
           ! compute gridpoint coordinates
           call idx2ijk(ix,iy,glob_row,idim,idim)
           ! x, y coordinates
-          x = (ix-1)*deltah
-          y = (iy-1)*deltah
+          x = (ix)*deltah
+          y = (iy)*deltah
           
           zt(k) = f_(x,y)
           ! internal point: build discretization
diff --git a/test/pdegen/psb_d_pde3d.F90 b/test/pdegen/psb_d_pde3d.F90
index 982e582c..57c5905d 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+1)
+    deltah   = done/(idim+2)
     sqdeltah = deltah*deltah
     deltah2  = (2*done)* deltah
 
@@ -496,9 +496,9 @@ contains
           ! compute gridpoint coordinates
           call idx2ijk(ix,iy,iz,glob_row,idim,idim,idim)
           ! x, y, z coordinates
-          x = (ix-1)*deltah
-          y = (iy-1)*deltah
-          z = (iz-1)*deltah
+          x = (ix)*deltah
+          y = (iy)*deltah
+          z = (iz)*deltah
           zt(k) = f_(x,y,z)
           ! internal point: build discretization
           !
diff --git a/test/pdegen/psb_s_pde2d.F90 b/test/pdegen/psb_s_pde2d.F90
index 1df7b138..43ad13a5 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+1)
+    deltah   = sone/(idim+2)
     sqdeltah = deltah*deltah
     deltah2  = (2*sone)* deltah
 
@@ -467,8 +467,8 @@ contains
           ! compute gridpoint coordinates
           call idx2ijk(ix,iy,glob_row,idim,idim)
           ! x, y coordinates
-          x = (ix-1)*deltah
-          y = (iy-1)*deltah
+          x = (ix)*deltah
+          y = (iy)*deltah
           
           zt(k) = f_(x,y)
           ! internal point: build discretization
diff --git a/test/pdegen/psb_s_pde3d.F90 b/test/pdegen/psb_s_pde3d.F90
index ac4dfbdf..86683196 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+1)
+    deltah   = sone/(idim+2)
     sqdeltah = deltah*deltah
     deltah2  = (2*sone)* deltah
 
@@ -496,9 +496,9 @@ contains
           ! compute gridpoint coordinates
           call idx2ijk(ix,iy,iz,glob_row,idim,idim,idim)
           ! x, y, z coordinates
-          x = (ix-1)*deltah
-          y = (iy-1)*deltah
-          z = (iz-1)*deltah
+          x = (ix)*deltah
+          y = (iy)*deltah
+          z = (iz)*deltah
           zt(k) = f_(x,y,z)
           ! internal point: build discretization
           !