diff --git a/esphome/components/image/__init__.py b/esphome/components/image/__init__.py
index e5a205f1e0..e80ba4498f 100644
--- a/esphome/components/image/__init__.py
+++ b/esphome/components/image/__init__.py
@@ -1,18 +1,17 @@
 from __future__ import annotations
 
-import logging
-
 import hashlib
 import io
+import logging
 from pathlib import Path
 import re
+
 from magic import Magic
 
-from esphome import core
-from esphome.components import font
-from esphome import external_files
-import esphome.config_validation as cv
+from esphome import core, external_files
 import esphome.codegen as cg
+from esphome.components import font
+import esphome.config_validation as cv
 from esphome.const import (
     CONF_DITHER,
     CONF_FILE,
@@ -239,12 +238,11 @@ CONFIG_SCHEMA = cv.All(font.validate_pillow_installed, IMAGE_SCHEMA)
 
 def load_svg_image(file: bytes, resize: tuple[int, int]):
     # Local import only to allow "validate_pillow_installed" to run *before* importing it
-    from PIL import Image
-
     # This import is only needed in case of SVG images; adding it
     # to the top would force configurations not using SVG to also have it
     # installed for no reason.
     from cairosvg import svg2png
+    from PIL import Image
 
     if resize:
         req_width, req_height = resize
@@ -274,6 +272,9 @@ async def to_code(config):
     elif conf_file[CONF_SOURCE] == SOURCE_WEB:
         path = compute_local_image_path(conf_file).as_posix()
 
+    else:
+        raise core.EsphomeError(f"Unknown image source: {conf_file[CONF_SOURCE]}")
+
     try:
         with open(path, "rb") as f:
             file_contents = f.read()