diff --git a/src/Type_gcmarray.jl b/src/Type_gcmarray.jl
index 72051c43..8e52c491 100644
--- a/src/Type_gcmarray.jl
+++ b/src/Type_gcmarray.jl
@@ -236,9 +236,9 @@ end
 
 function Base.similar(A::gcmarray;m::varmeta=defaultmeta)
     if ndims(A)==1
-        B=gcmarray(A.grid,eltype(A),copy(A.fSize),copy(A.fIndex); meta=m)
+        B=gcmarray(similar(A.grid),eltype(A),copy(A.fSize),copy(A.fIndex); meta=m)
     else
-        B=gcmarray(A.grid,eltype(A),copy(A.fSize),copy(A.fIndex),size(A,2); meta=m)
+        B=gcmarray(similar(A.grid),eltype(A),copy(A.fSize),copy(A.fIndex),size(A,2); meta=m)
     end
     return B
 end
@@ -252,9 +252,9 @@ function Base.similar(bc::Broadcast.Broadcasted{Broadcast.ArrayStyle{gcmarray}},
   A = find_gcmarray(bc)
   # Create the gcmarray output:
   if ndims(A)==1
-        B=gcmarray(A.grid,ElType,A.fSize,A.fIndex)
+        B=gcmarray(similar(A.grid),ElType,copy(A.fSize),copy(A.fIndex))
   else
-        B=gcmarray(A.grid,ElType,A.fSize,A.fIndex,size(A,2))
+        B=gcmarray(similar(A.grid),ElType,copy(A.fSize),copy(A.fIndex),size(A,2))
   end
   return B
 end
diff --git a/src/Type_gcmvector.jl b/src/Type_gcmvector.jl
index 5dd43bb1..b4b6c963 100644
--- a/src/Type_gcmvector.jl
+++ b/src/Type_gcmvector.jl
@@ -65,7 +65,7 @@ function Base.similar(bc::Broadcast.Broadcasted{Broadcast.ArrayStyle{gcmvector}}
   # Scan the inputs for the gcmarray:
   A = find_gcmvector(bc)
   # Create the gcmvector output:
-  return gcmvector{ElType,ndims(A)}(A.grid,similar(A.f),A.fSize,A.fIndex)
+  return gcmvector{ElType,ndims(A)}(A.grid,similar(A.f),copy(A.fSize),copy(A.fIndex))
 end
 
 find_gcmvector(bc::Base.Broadcast.Broadcasted) = find_gcmvector(bc.args)
diff --git a/src/Types.jl b/src/Types.jl
index 3c83b882..ce9e79b9 100644
--- a/src/Types.jl
+++ b/src/Types.jl
@@ -48,6 +48,10 @@ struct gcmgrid
   write::Function
 end
 
+copy_if_isarray(x) = isa(x,Array) ? copy(x) : x
+
+Base.similar(g::gcmgrid)=gcmgrid(g.path, g.class, g.nFaces, copy(g.fSize), copy_if_isarray(g.ioSize), g.ioPrec, g.read, g.write)
+
 """
     varmeta