diff --git a/wimf/__init__.py b/wimf/__init__.py
index dda4e80..226f9a8 100644
--- a/wimf/__init__.py
+++ b/wimf/__init__.py
@@ -47,9 +47,9 @@ def save(path, image, **kwargs):
     raw = encoder.encode(**encode_args)
 
     try:
-        from . import wimf_cpp
+        from .wimf_cpp import c_save_file
 
-        wimf_cpp.c_save_file(path, raw)
+        c_save_file(path, raw)
     except (ImportError, AttributeError):
         with _builtins.open(path, "wb") as f:
             f.write(raw)
diff --git a/wimf/animation.py b/wimf/animation.py
index 2536c0f..5c8d354 100644
--- a/wimf/animation.py
+++ b/wimf/animation.py
@@ -10,7 +10,9 @@
 try:
     from . import wimf_cpp  # type: ignore[attr-defined]
 except ImportError:
-    pass
+    logging.getLogger(__name__).debug(
+        "Optional module '.wimf_cpp' could not be imported; using Python implementation."
+    )
 
 logger = logging.getLogger(__name__)
 
diff --git a/wimf/cat.py b/wimf/cat.py
index c7e9b25..f368e7c 100644
--- a/wimf/cat.py
+++ b/wimf/cat.py
@@ -14,7 +14,7 @@ def render_terminal(wimf_img, width=None):
     if width is None:
         try:
             width = os.get_terminal_size().columns
-        except:
+        except OSError:
             width = 80
 
     # Account for terminal character aspect ratio (~2:1)
diff --git a/wimf/cli.py b/wimf/cli.py
index 4283c2c..e6ef55a 100644
--- a/wimf/cli.py
+++ b/wimf/cli.py
@@ -12,8 +12,6 @@
 import numpy as np
 from PIL import ExifTags, Image, ImageSequence
 
-from wimf.io import loadImage, saveImage
-
 logger = logging.getLogger(__name__)
 
 
diff --git a/wimf/codec.py b/wimf/codec.py
index 9d55846..fc72c14 100644
--- a/wimf/codec.py
+++ b/wimf/codec.py
@@ -8,8 +8,9 @@
 
 try:
     from . import wimf_cpp  # type: ignore[attr-defined]
-except ImportError:
-    pass
+except ImportError as exc:
+    # Optional C++ acceleration module is unavailable; fall back to Python implementation.
+    logger.debug("wimf_cpp extension not available, using Python codec path: %s", exc)
 import multiprocessing
 from concurrent.futures import ThreadPoolExecutor
 
diff --git a/wimf/test_core.py b/wimf/test_core.py
index 7eb84a6..2ee2cb6 100644
--- a/wimf/test_core.py
+++ b/wimf/test_core.py
@@ -1,5 +1,3 @@
-import os
-
 import numpy as np
 from PIL import Image
 
diff --git a/wimf/viewer.py b/wimf/viewer.py
index 091c2de..3010909 100644
--- a/wimf/viewer.py
+++ b/wimf/viewer.py
@@ -177,7 +177,7 @@ def main():
 
     if os.path.exists(p):
         root = tk.Tk()
-        viewer = WIMFViewer(root, p)
+        WIMFViewer(root, p)
         root.mainloop()
     else:
         print(f"File not found: {p}")