diff --git a/python/damask/VERSION b/python/damask/VERSION
index 278b0bc78..beee5f0d7 100644
--- a/python/damask/VERSION
+++ b/python/damask/VERSION
@@ -1 +1 @@
-v3.0.0-alpha5-441-g8b5122f52
+v3.0.0-alpha5-457-g75040047c
diff --git a/python/damask/_colormap.py b/python/damask/_colormap.py
index 2c7f01d94..1ccc292e6 100644
--- a/python/damask/_colormap.py
+++ b/python/damask/_colormap.py
@@ -250,7 +250,7 @@ class Colormap(mpl.colors.ListedColormap):
                np.logical_or (np.isnan(field), field == gap))                                       # mask NaN (and gap if present)
 
         l,r = (field[mask].min(),field[mask].max()) if bounds is None else \
-              np.array(bounds,float)[:2]
+              (bounds[0],bounds[1])
 
         delta,avg = r-l,0.5*abs(r+l)
 
diff --git a/python/damask/_grid.py b/python/damask/_grid.py
index 002d00259..eefd1e0be 100644
--- a/python/damask/_grid.py
+++ b/python/damask/_grid.py
@@ -428,7 +428,7 @@ class Grid:
             seeds_p = np.vstack((seeds_p-np.array([0.,size[1],0.]),seeds_p,seeds_p+np.array([0.,size[1],0.])))
             seeds_p = np.vstack((seeds_p-np.array([0.,0.,size[2]]),seeds_p,seeds_p+np.array([0.,0.,size[2]])))
         else:
-            weights_p = weights
+            weights_p = np.array(weights,float)
             seeds_p   = seeds
 
         coords = grid_filters.coordinates0_point(cells,size).reshape(-1,3)
@@ -841,7 +841,8 @@ class Grid:
         if not set(directions).issubset(valid):
             raise ValueError(f'invalid direction {set(directions).difference(valid)} specified')
 
-        mat = np.flip(self.material, (valid.index(d) for d in directions if d in valid))
+
+        mat = np.flip(self.material, [valid.index(d) for d in directions if d in valid])
 
         return Grid(material = mat,
                     size     = self.size,
@@ -973,14 +974,13 @@ class Grid:
             Updated grid-based geometry.
 
         """
-        if fill is None: fill = np.nanmax(self.material) + 1
-        dtype = float if isinstance(fill,float) or self.material.dtype in np.sctypes['float'] else int
-
         material = self.material
         # These rotations are always applied in the reference coordinate system, i.e. (z,x,z) not (z,x',z'')
         # see https://www.cs.utexas.edu/~theshark/courses/cs354/lectures/cs354-14.pdf
         for angle,axes in zip(R.as_Euler_angles(degrees=True)[::-1], [(0,1),(1,2),(0,1)]):
-            material_temp = ndimage.rotate(material,angle,axes,order=0,prefilter=False,output=dtype,cval=fill)
+            material_temp = ndimage.rotate(material,angle,axes,order=0,prefilter=False,
+                                           output=self.material.dtype,
+                                           cval=np.nanmax(self.material) + 1 if fill is None else fill)
             # avoid scipy interpolation errors for rotations close to multiples of 90°
             material = material_temp if np.prod(material_temp.shape) != np.prod(material.shape) else \
                        np.rot90(material,k=np.rint(angle/90.).astype(int),axes=axes)
@@ -1031,10 +1031,8 @@ class Grid:
         """
         offset_ = np.array(offset,int) if offset is not None else np.zeros(3,int)
         cells_ = np.array(cells,int) if cells is not None else self.cells
-        if fill is None: fill = np.nanmax(self.material) + 1
-        dtype = float if int(fill) != fill or self.material.dtype in np.sctypes['float'] else int
 
-        canvas = np.full(cells_,fill,dtype)
+        canvas = np.full(cells_,np.nanmax(self.material) + 1 if fill is None else fill,self.material.dtype)
 
         LL = np.clip( offset_,           0,np.minimum(self.cells,     cells_+offset_))
         UR = np.clip( offset_+cells_,    0,np.minimum(self.cells,     cells_+offset_))
@@ -1067,13 +1065,11 @@ class Grid:
             Updated grid-based geometry.
 
         """
-        def mp(entry, mapper):
-            return mapper[entry] if entry in mapper else entry
+        material = self.material.copy()
+        for f,t in zip(from_material,to_material):        # ToDo Python 3.10 has strict mode for zip
+            material[self.material==f] = t
 
-        mp = np.vectorize(mp)
-        mapper = dict(zip(from_material,to_material))
-
-        return Grid(material = mp(self.material,mapper).reshape(self.cells),
+        return Grid(material = material,
                     size     = self.size,
                     origin   = self.origin,
                     comments = self.comments+[util.execution_stamp('Grid','substitute')],
diff --git a/src/YAML_types.f90 b/src/YAML_types.f90
index 5884c2850..6e926b39e 100644
--- a/src/YAML_types.f90
+++ b/src/YAML_types.f90
@@ -62,6 +62,8 @@ module YAML_types
       tNode_get_byKey_as1dString   => tNode_get_byKey_as1dString
     procedure :: &
       getKey                       => tNode_get_byIndex_asKey
+    procedure :: &
+      Keys                         => tNode_getKeys
     procedure :: &
       getIndex                     => tNode_get_byKey_asIndex
     procedure :: &
@@ -625,6 +627,32 @@ function tNode_get_byIndex_asKey(self,i)  result(key)
 end function tNode_get_byIndex_asKey
 
 
+!--------------------------------------------------------------------------------------------------
+!> @brief Get all keys from a dictionary
+!--------------------------------------------------------------------------------------------------
+function tNode_getKeys(self) result(keys)
+
+  class(tNode), intent(in) :: self
+  character(len=:), dimension(:), allocatable :: keys
+
+  character(len=pStringLen), dimension(:), allocatable :: temp
+  integer :: j, l
+
+  allocate(temp(self%length))
+  l = 0
+  do j = 1, self%length
+    temp(j) = self%getKey(j)
+    l = max(len_trim(temp(j)),l)
+  end do
+
+  allocate(character(l)::keys(self%length))
+  do j = 1, self%length
+    keys(j) = trim(temp(j))
+  end do
+
+end function tNode_getKeys
+
+
 !-------------------------------------------------------------------------------------------------
 !> @brief Checks if a given key/item is present in the dict/list
 !-------------------------------------------------------------------------------------------------
diff --git a/src/material.f90 b/src/material.f90
index 52940ee4a..1e3a4b4ec 100644
--- a/src/material.f90
+++ b/src/material.f90
@@ -108,8 +108,14 @@ subroutine parse()
   homogenizations => config_material%get('homogenization')
 
   call sanityCheck(materials, homogenizations)
+
+#if defined (__GFORTRAN__)
   material_name_phase          = getKeys(phases)
   material_name_homogenization = getKeys(homogenizations)
+#else
+  material_name_phase          = phases%Keys()
+  material_name_homogenization = homogenizations%Keys()
+#endif
 
   allocate(homogenization_Nconstituents(homogenizations%length))
   do h=1, homogenizations%length
@@ -203,9 +209,9 @@ subroutine sanityCheck(materials,homogenizations)
 
 end subroutine sanityCheck
 
-
+#if defined (__GFORTRAN__)
 !--------------------------------------------------------------------------------------------------
-!> @brief Get all keys from a dictionary
+!> @brief %keys() is broken on gfortran
 !--------------------------------------------------------------------------------------------------
 function getKeys(dict)
 
@@ -228,5 +234,6 @@ function getKeys(dict)
   end do
 
 end function getKeys
+#endif
 
 end module material