diff --git a/src/lava/proc/io/__init__.py b/src/lava/proc/io/__init__.py
index 4db497580..60115fc4c 100644
--- a/src/lava/proc/io/__init__.py
+++ b/src/lava/proc/io/__init__.py
@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # See: https://spdx.org/licenses/
 
-from . import reset, source, sink, dataloader, encoder
+from . import reset, source, sink, dataloader, encoder, injector, extractor
 
-__all__ = ['reset', 'source', 'sink', 'dataloader', 'encoder']
+__all__ = ['reset', 'source', 'sink', 'dataloader', 'encoder', 'injector',
+           'extractor']
diff --git a/src/lava/proc/io/utils.py b/src/lava/proc/io/utils.py
index 9bccdba48..7f8bc0ec7 100644
--- a/src/lava/proc/io/utils.py
+++ b/src/lava/proc/io/utils.py
@@ -222,7 +222,7 @@ def validate_shape(shape: ty.Tuple[int, ...]):
                         f"<shape> = {shape}.")
 
     for s in shape:
-        if not isinstance(s, int):
+        if not np.issubdtype(type(s), int):
             raise TypeError("Expected all elements of <shape> to be of "
                             f"type int. Got <shape> = {shape}.")
         if s <= 0:
@@ -238,7 +238,7 @@ def validate_buffer_size(buffer_size: int):
     buffer_size : int
         Buffer size to validate.
     """
-    if not isinstance(buffer_size, int):
+    if not np.issubdtype(type(buffer_size), int):
         raise TypeError("Expected <buffer_size> to be of type int. Got "
                         f"<buffer_size> = {buffer_size}.")
     if buffer_size <= 0: