diff --git a/src/Cells.jl b/src/Cells.jl
index de5ed57..d015a08 100644
--- a/src/Cells.jl
+++ b/src/Cells.jl
@@ -644,7 +644,7 @@ function flatten(c::CellArray)
                       sgn*c.mag*sin(c.rot) c.mag*cos(c.rot)])
     for i in 1:c.row, j in 1:c.col
         pt = (i-1) * c.deltarow + (j-1) * c.deltacol
-        append!(polys, a.(flatten(c.cell)))
+        append!(polys, a.(flatten(c.cell) .+ pt))
         # append!(polys, a.(c.cell.elements .+ pt))
         # for r in c.cell.refs
         #     append!(polys, a.(flatten(r) .+ pt))
diff --git a/test/runtests.jl b/test/runtests.jl
index 2eb729d..bd71fc5 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -305,6 +305,10 @@ end
     @test bounds(c′) ≈ (bounds(c) + Point(10.0,10.0))
     @test bounds(c2ref′) ≈ (bounds(c2ref) + Point(10.,10.))
 
+    # Test `flatten!` when encountering a CellReference
+    flatten!(c)
+    @test bounds(c) == bounds(c2ref)
+
     # More setup
     c = Cell("main")
     c2 = Cell("rect")
@@ -317,7 +321,10 @@ end
     # Test bounds with cell arrays
     @test bounds(c) == Rectangle(95,95)
 
-    # TODO: Tests for `flatten`
+    # Test `flatten!` when encountering a CellArray
+    flatten!(c)
+    @test bounds(c) == Rectangle(95,95)
+
 end
 
 @testset "Paths" begin