diff --git a/GPUSimulators/common/arrays/array2d.py b/GPUSimulators/common/arrays/array2d.py
index b63acf1..03452ad 100644
--- a/GPUSimulators/common/arrays/array2d.py
+++ b/GPUSimulators/common/arrays/array2d.py
@@ -36,4 +36,14 @@ class BaseArray2D(object):
             raise ValueError("Wrong size of data type")
 
         if np.isfortran(cpu_data):
-            raise TypeError("Wrong datatype (Fortran, expected C)")
\ No newline at end of file
+            raise TypeError("Wrong datatype (Fortran, expected C)")
+
+    def check(self, x, y, nx, ny, cpu_data):
+        if nx != cpu_data.shape[1]:
+            raise ValueError
+        if ny != cpu_data.shape[0]:
+            raise ValueError
+        if x + nx > self.nx + 2 * self.x_halo:
+            raise ValueError
+        if y + ny > self.ny + 2 * self.y_halo:
+            raise ValueError
diff --git a/GPUSimulators/common/arrays/cuda/arkawa2d.py b/GPUSimulators/common/arrays/cuda/arkawa2d.py
index 23730ed..df5f2d4 100644
--- a/GPUSimulators/common/arrays/cuda/arkawa2d.py
+++ b/GPUSimulators/common/arrays/cuda/arkawa2d.py
@@ -25,4 +25,4 @@ class ArakawaA2D(BaseArakawaA2D):
                               + f"has average {var_sum / (gpu_variable.nx * gpu_variable.ny)}")
 
             if np.isnan(var_sum):
-                raise ValueError("Data contains NaN values!")
\ No newline at end of file
+                raise ValueError("Data contains NaN values!")
diff --git a/GPUSimulators/common/arrays/cuda/array2d.py b/GPUSimulators/common/arrays/cuda/array2d.py
index 19a0140..99d913e 100644
--- a/GPUSimulators/common/arrays/cuda/array2d.py
+++ b/GPUSimulators/common/arrays/cuda/array2d.py
@@ -58,10 +58,7 @@ class CudaArray2D(BaseArray2D):
             # Non-pagelocked: cpu_data = np.empty((ny, nx), dtype=np.float32)
             # cpu_data = self.memorypool.allocate((ny, nx), dtype=np.float32)
 
-        assert nx == cpu_data.shape[1]
-        assert ny == cpu_data.shape[0]
-        assert x + nx <= self.nx + 2 * self.x_halo
-        assert y + ny <= self.ny + 2 * self.y_halo
+        self.check(x, y, nx, ny, cpu_data)
 
         # Create a copy object from device to host
         copy = cuda.Memcpy2D()
@@ -93,10 +90,7 @@ class CudaArray2D(BaseArray2D):
         else:
             x, y, nx, ny = extent
 
-        assert (nx == cpu_data.shape[1])
-        assert (ny == cpu_data.shape[0])
-        assert (x + nx <= self.nx + 2 * self.x_halo)
-        assert (y + ny <= self.ny + 2 * self.y_halo)
+        self.check(x, y, nx, ny, cpu_data)
 
         # Create a copy object from device to host
         copy = cuda.Memcpy2D()
@@ -113,4 +107,4 @@ class CudaArray2D(BaseArray2D):
         copy.width_in_bytes = int(nx) * cpu_data.itemsize
         copy.height = int(ny)
 
-        copy(stream)
\ No newline at end of file
+        copy(stream)