diff --git a/oks_cli/cluster.py b/oks_cli/cluster.py
index 75b15ff..9e7ef5b 100644
--- a/oks_cli/cluster.py
+++ b/oks_cli/cluster.py
@@ -381,7 +381,7 @@ def _create_cluster(project_name, cluster_config, output):
 @click.option('--cp-multi-az', '-m', is_flag=True, help="Enable control plane multi AZ")
 @click.option('--dry-run', is_flag=True, help="Client dry-run, only print the object that would be sent, without sending it")
 @click.option('--output', '-o', type=click.Choice(["json", "yaml"]), help="Specify output format, by default is json")
-@click.option('--filename', '-f', type=click.File("r"), help="Path to file to use to create the cluster ")
+@click.option('--filename', '-f', type=click.File("rb"), help="Path to file to use to create the cluster ")
 @click.option('--profile', help="Configuration profile to use", shell_complete=profile_completer)
 @click.option('--set', 'set_fields', multiple=True, help="Set arbitrary nested fields, e.g. auth.oidc.issuer-url=value")
 @click.pass_context
@@ -479,7 +479,7 @@ def cluster_create_command(ctx, project_name, cluster_name, description, admin,
 @click.option('--control-plane', shell_complete=shell_completions, help="Controlplane plan")
 @click.option('--dry-run', is_flag=True, help="Client dry-run, only print the object that would be sent, without sending it")
 @click.option('--output', '-o',  type=click.Choice(["json", "yaml"]), help="Specify output format, by default is json")
-@click.option('--filename', '-f', type=click.File("r"), help="Path to file to use to update the cluster ")
+@click.option('--filename', '-f', type=click.File("rb"), help="Path to file to use to update the cluster ")
 @click.option('--profile', help="Configuration profile to use", shell_complete=profile_completer)
 @click.option('--set', 'set_fields', multiple=True, help="Set arbitrary nested fields, e.g. auth.oidc.issuer-url=value")
 @click.pass_context
@@ -822,7 +822,7 @@ def nodepool_list(ctx):
 @click.option('--zone', '-z', multiple=True, help="Provide zone(s)")
 @click.option('--output', '-o', type=click.Choice(["json", "yaml"]), help="Specify output format, by default is json")
 @click.option('--dry-run', is_flag=True, help="Run without any action")
-@click.option('--filename', '-f', type=click.File("r"), help="Path to file to use to create the Nodepool")
+@click.option('--filename', '-f', type=click.File("rb"), help="Path to file to use to create the Nodepool")
 @click.pass_context
 def setup_worker_pool(ctx, nodepool_name, count, vmtype, zone, output, dry_run, filename):
     """Create a new nodepool in the cluster, optionally from a file or parameters."""
diff --git a/oks_cli/project.py b/oks_cli/project.py
index 95f21d1..80e62e6 100644
--- a/oks_cli/project.py
+++ b/oks_cli/project.py
@@ -193,7 +193,7 @@ def project_list(ctx, project_name, deleted, plain, msword, uuid, watch, output,
 @click.option('--disable-api-termination', type=click.BOOL, help="Disable delete action by API")
 @click.option('--dry-run', is_flag=True, help="Client dry-run, only print the object that would be sent, without sending it")
 @click.option('--output', '-o', type=click.Choice(["json", "yaml", "silent"]), help="Specify output format, by default is json")
-@click.option('--filename', '-f', type=click.File("r"), help="Path to file to use to create the project")
+@click.option('--filename', '-f', type=click.File("rb"), help="Path to file to use to create the project")
 @click.option('--profile', help="Configuration profile to use", shell_complete=profile_completer)
 @click.option('--set', 'set_fields', multiple=True, help="Set arbitrary nested fields, e.g. auth.oidc.issuer-url=value")
 @click.pass_context
diff --git a/oks_cli/utils.py b/oks_cli/utils.py
index 432b8db..f237a3b 100644
--- a/oks_cli/utils.py
+++ b/oks_cli/utils.py
@@ -1,4 +1,5 @@
 import click
+import codecs
 import os
 import subprocess
 import logging
@@ -753,6 +754,15 @@ def remove_jwt_token(token_type):
 
 def detect_and_parse_input(input_data):
     """Parse input as JSON or YAML; raise error if invalid."""
+    if isinstance(input_data, bytes):
+        try:
+            if input_data.startswith((codecs.BOM_UTF16_LE, codecs.BOM_UTF16_BE)):
+                input_data = input_data.decode("utf-16")
+            else:
+                input_data = input_data.decode("utf-8-sig")
+        except UnicodeDecodeError:
+            raise click.BadParameter("Input file is neither valid JSON nor YAML.")
+
     try:
         return json.loads(input_data)
     except json.JSONDecodeError: