diff --git a/src/H5D.c b/src/H5D.c
index bf51e1cc5af..7252b83be71 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -1247,18 +1247,18 @@ H5Dget_chunk_info_by_coord(hid_t dset_id, const hsize_t *offset, unsigned *filte
  *
  *        typedef int (*H5D_chunk_iter_op_t)(
  *            const hsize_t *offset,
- *            uint32_t filter_mask,
+ *            unsigned filter_mask,
  *            haddr_t addr,
- *            uint32_t nbytes,
+ *            hsize_t size,
  *            void *op_data);
  *
  *      H5D_chunk_iter_op_t parameters:
- *          hsize_t *offset;        IN/OUT: Array of starting logical coordinates of chunk.
- *          uint32_t filter_mask;   IN: Filter mask of chunk.
- *          haddr_t addr;           IN: Offset in file of chunk data.
- *          uint32_t nbytes;        IN: Size in number of bytes of chunk data in file.
- *          void *op_data;          IN/OUT: Pointer to any user-defined data
- *                                  associated with the operation.
+ *          hsize_t *offset;        IN/OUT: Logical position of the chunk’s first element in units of dataset
+ *                                          elements
+ *          unsigned filter_mask;   IN: Bitmask indicating the filters used when the chunk was written haddr_t
+ *          addr;                   IN: Chunk address in the file
+ *          hsize_t;                IN: Chunk size in bytes, 0 if the chunk does not exist
+ *          void *op_data;          IN/OUT: Pointer to any user-defined data associated with the operation.
  *
  *      The return values from an operator are:
  *          Zero (H5_ITER_CONT) causes the iterator to continue, returning zero when all
diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index ed1f4945eb2..1f94259542c 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -7686,8 +7686,8 @@ H5D__chunk_iter_cb(const H5D_chunk_rec_t *chunk_rec, void *udata)
     FUNC_ENTER_PACKAGE_NOERR
 
     /* Check for callback failure and pass along return value */
-    if ((ret_value = (data->op)(chunk_rec->scaled, chunk_rec->filter_mask, chunk_rec->chunk_addr,
-                                chunk_rec->nbytes, data->op_data)) < 0)
+    if ((ret_value = (data->op)(chunk_rec->scaled, (unsigned)chunk_rec->filter_mask, chunk_rec->chunk_addr,
+                                (hsize_t)chunk_rec->nbytes, data->op_data)) < 0)
         HERROR(H5E_DATASET, H5E_CANTNEXT, "iteration operator failed");
 
     FUNC_LEAVE_NOAPI(ret_value)
diff --git a/src/H5Dpublic.h b/src/H5Dpublic.h
index cac39707b0f..96e2f47f893 100644
--- a/src/H5Dpublic.h
+++ b/src/H5Dpublic.h
@@ -239,7 +239,7 @@ typedef herr_t (*H5D_gather_func_t)(const void *dst_buf, size_t dst_buf_bytes_us
  *          \li A negative (#H5_ITER_ERROR) causes the iterator to immediately
  *              return that value, indicating failure.
  */
-typedef int (*H5D_chunk_iter_op_t)(const hsize_t *offset, uint32_t filter_mask, haddr_t addr, uint32_t nbytes,
+typedef int (*H5D_chunk_iter_op_t)(const hsize_t *offset, unsigned filter_mask, haddr_t addr, hsize_t size,
                                    void *op_data);
 //! <!-- [H5D_chunk_iter_op_t_snip] -->
 
diff --git a/test/chunk_info.c b/test/chunk_info.c
index fa6b062d553..03f827f4da2 100644
--- a/test/chunk_info.c
+++ b/test/chunk_info.c
@@ -1668,33 +1668,36 @@ test_chunk_info_version2_btrees(char *filename, hid_t fapl)
 
 typedef struct chunk_iter_info_t {
     hsize_t  offset[2];
-    uint32_t filter_mask;
+    unsigned filter_mask;
     haddr_t  addr;
-    uint32_t nbytes;
+    hsize_t  size;
 } chunk_iter_info_t;
 
+typedef struct chunk_iter_udata_t {
+    chunk_iter_info_t *chunk_info;
+    int                last_index;
+} chunk_iter_udata_t;
+
 static int
-iter_cb(const hsize_t *offset, uint32_t filter_mask, haddr_t addr, uint32_t nbytes, void *op_data)
+iter_cb(const hsize_t *offset, unsigned filter_mask, haddr_t addr, hsize_t size, void *op_data)
 {
-    chunk_iter_info_t **chunk_info = (chunk_iter_info_t **)op_data;
+    chunk_iter_udata_t *cidata = (chunk_iter_udata_t *)op_data;
+    int                 idx    = cidata->last_index + 1;
 
-    (*chunk_info)->offset[0]   = offset[0];
-    (*chunk_info)->offset[1]   = offset[1];
-    (*chunk_info)->filter_mask = filter_mask;
-    (*chunk_info)->addr        = addr;
-    (*chunk_info)->nbytes      = nbytes;
+    cidata->chunk_info[idx].offset[0]   = offset[0];
+    cidata->chunk_info[idx].offset[1]   = offset[1];
+    cidata->chunk_info[idx].filter_mask = filter_mask;
+    cidata->chunk_info[idx].addr        = addr;
+    cidata->chunk_info[idx].size        = size;
 
-    /* printf("offset: [%lld, %lld], addr: %ld, size: %d, filter mask: %d\n", offset[0], offset[1], addr,
-     * nbytes, filter_mask); */
-
-    *chunk_info += 1;
+    cidata->last_index++;
 
     return H5_ITER_CONT;
 }
 
 static int
-iter_cb_stop(const hsize_t H5_ATTR_UNUSED *offset, uint32_t H5_ATTR_UNUSED filter_mask,
-             haddr_t H5_ATTR_UNUSED addr, uint32_t H5_ATTR_UNUSED nbytes, void *op_data)
+iter_cb_stop(const hsize_t H5_ATTR_UNUSED *offset, unsigned H5_ATTR_UNUSED filter_mask,
+             haddr_t H5_ATTR_UNUSED addr, hsize_t H5_ATTR_UNUSED size, void *op_data)
 {
     chunk_iter_info_t **chunk_info = (chunk_iter_info_t **)op_data;
     *chunk_info += 1;
@@ -1702,8 +1705,8 @@ iter_cb_stop(const hsize_t H5_ATTR_UNUSED *offset, uint32_t H5_ATTR_UNUSED filte
 }
 
 static int
-iter_cb_fail(const hsize_t H5_ATTR_UNUSED *offset, uint32_t H5_ATTR_UNUSED filter_mask,
-             haddr_t H5_ATTR_UNUSED addr, uint32_t H5_ATTR_UNUSED nbytes, void *op_data)
+iter_cb_fail(const hsize_t H5_ATTR_UNUSED *offset, unsigned H5_ATTR_UNUSED filter_mask,
+             haddr_t H5_ATTR_UNUSED addr, hsize_t H5_ATTR_UNUSED size, void *op_data)
 {
     chunk_iter_info_t **chunk_info = (chunk_iter_info_t **)op_data;
     *chunk_info += 1;