diff --git a/src/core/CL/cl_kernels/flatten.cl b/src/core/CL/cl_kernels/flatten.cl
index df0f9c4..02694f7 100644
--- a/src/core/CL/cl_kernels/flatten.cl
+++ b/src/core/CL/cl_kernels/flatten.cl
@@ -23,12 +23,13 @@
  */
 #include "helpers.h"
 
-#if defined(DATA_TYPE) && defined(SRC_WIDTH) && defined(SRC_HEIGHT)
+#if defined(DATA_TYPE) && defined(SRC_WIDTH) && defined(SRC_HEIGHT) && defined(SRC_DEPTH)
 
 /** This opencl kernel flattens the first 3 dimensions of the input tensor
  *
  * @note Datatype should be given as a preprocessor argument using -DDATA_TYPE=type. e.g. -DDATA_TYPE=float
- * @note The width and height of the input tensor must be passed at compile time using -DSRC_WIDTH and -DSRC_HEIGHT. e.g. -DSRC_WIDTH=24, -DSRC_HEIGHT=24
+ * @note The width, height and depth of the input tensor must be passed at compile time using -DSRC_WIDTH, -DSRC_HEIGHT and -DSRC_DEPTH. e.g. -DSRC_WIDTH=24, -DSRC_HEIGHT=24, -DSRC_DEPTH=16
+ * @note If the output has 3 dimensions, the 2nd dimension of the output tensor must be passed at compile time using -DDST_DIM1. e.g -DDST_DIM1=3
  *
  * @param[in]  src_ptr                           Pointer to the source tensor. Supported data types: U8/S8/QASYMM8/U16/S16/F16/U32/S32/F32
  * @param[in]  src_stride_x                      Stride of the source tensor in X dimension (in bytes)
@@ -37,20 +38,38 @@
  * @param[in]  src_step_y                        src_stride_y * number of elements along Y processed per workitem(in bytes)
  * @param[in]  src_stride_z                      Stride of the source tensor in Z dimension (in bytes)
  * @param[in]  src_step_z                        src_stride_z * number of elements along Y processed per workitem(in bytes)
+ * @param[in]  src_stride_w                      Stride of the source tensor in W dimension (in bytes)
+ * @param[in]  src_step_w                        src_stride_w * number of elements along Y processed per workitem(in bytes)
  * @param[in]  src_offset_first_element_in_bytes The offset of the first element in the source tensor
  * @param[out] dst_ptr                           Pointer to the destination tensor. Same as @p src_ptr
  * @param[in]  dst_stride_x                      Stride of the destination tensor in X dimension (in bytes)
  * @param[in]  dst_step_x                        dst_stride_x * number of elements along X processed per workitem(in bytes)
+ * @param[in]  dst_stride_y                      Stride of the destination tensor in Y dimension (in bytes)
+ * @param[in]  dst_step_y                        dst_stride_y * number of elements along Y processed per workitem(in bytes)
+ * @param[in]  dst_stride_z                      Stride of the destination tensor in Z dimension (in bytes)
+ * @param[in]  dst_step_z                        dst_stride_z * number of elements along Z processed per workitem(in bytes)
  * @param[in]  dst_offset_first_element_in_bytes The offset of the first element in the destination tensor
  */
 __kernel void flatten(
-    TENSOR3D_DECLARATION(src),
-    VECTOR_DECLARATION(dst))
+    TENSOR4D_DECLARATION(src),
+    TENSOR3D_DECLARATION(dst))
 {
-    Tensor3D src = CONVERT_TO_TENSOR3D_STRUCT(src);
+    Tensor4D src = CONVERT_TO_TENSOR4D_STRUCT(src, SRC_DEPTH);
 
-    __global uchar *output_ptr = dst_ptr + dst_offset_first_element_in_bytes + (get_global_id(0) + get_global_id(1) * (int)SRC_WIDTH + get_global_id(2) * (int)(SRC_WIDTH * SRC_HEIGHT)) * sizeof(
-                                     DATA_TYPE);
+    uint c  = get_global_id(2) % SRC_DEPTH; // input feature map
+    uint b0 = get_global_id(2) / SRC_DEPTH; // batch id
+    uint b1 = 0;
+
+#if defined(DST_DIM1)
+    uint b_tmp = b0;
+    b0 = b_tmp % DST_DIM1; // batch id0
+    b1 = b_tmp / DST_DIM1; // batch id1
+#endif // defined(DST_DIM1)
+
+    __global uchar *output_ptr = dst_ptr + dst_offset_first_element_in_bytes +
+                                 (get_global_id(0) + get_global_id(1) * (uint)SRC_WIDTH + c * (uint)(SRC_WIDTH * SRC_HEIGHT)) * sizeof(DATA_TYPE) +
+                                 b0 * dst_stride_y +
+                                 b1 * dst_stride_z;
 
     *((__global DATA_TYPE *)output_ptr) = *((__global DATA_TYPE *)src.ptr);
 }