diff --git a/lib/python/qmk/cli/lint.py b/lib/python/qmk/cli/lint.py
index 8a128ce6d2..a05bd2fa7e 100644
--- a/lib/python/qmk/cli/lint.py
+++ b/lib/python/qmk/cli/lint.py
@@ -8,7 +8,7 @@ from milc import cli
 from qmk.decorators import automagic_keyboard, automagic_keymap
 from qmk.info import info_json
 from qmk.keyboard import keyboard_completer, keyboard_folder_or_all, is_all_keyboards, list_keyboards
-from qmk.keymap import locate_keymap, list_keymaps
+from qmk.keymap import locate_keymap, list_keymaps, is_valid_keymap_name
 from qmk.path import keyboard
 from qmk.git import git_get_ignored_files
 from qmk.c_parse import c_source_files, preprocess_c_file
@@ -245,18 +245,21 @@ def _handle_duplicating_code_defaults(kb, info):
 def keymap_check(kb, km):
     """Perform the keymap level checks.
     """
-    ok = True
     keymap_path = locate_keymap(kb, km)
 
     if not keymap_path:
-        ok = False
         cli.log.error("%s: Can't find %s keymap.", kb, km)
-        return ok
+        return False
 
     if km in INVALID_KM_NAMES:
-        ok = False
         cli.log.error("%s: The keymap %s should not exist!", kb, km)
-        return ok
+        return False
+
+    ok = True
+
+    if not is_valid_keymap_name(km):
+        cli.log.error(f'{kb}/{km}: Keymap name must contain only a-z, 0-9 and _!')
+        ok = False
 
     # Additional checks
     invalid_files = git_get_ignored_files(keymap_path.parent.as_posix())
diff --git a/lib/python/qmk/keymap.py b/lib/python/qmk/keymap.py
index 36a821ebda..4c7b391362 100644
--- a/lib/python/qmk/keymap.py
+++ b/lib/python/qmk/keymap.py
@@ -1,6 +1,7 @@
 """Functions that help you work with QMK keymaps.
 """
 import sys
+import re
 from pathlib import Path
 from subprocess import DEVNULL
 
@@ -239,6 +240,13 @@ def is_keymap_dir(keymap, c=True, json=True, additional_files=None):
             return True
 
 
+def is_valid_keymap_name(name):
+    """Returns True if the given keymap name contains only valid characters.
+    """
+    regex = re.compile(r'^[a-z0-9][a-z0-9_]+$')
+    return bool(regex.match(name))
+
+
 def generate_json(keymap, keyboard, layout, layers, macros=None):
     """Returns a `keymap.json` for the specified keyboard, layout, and layers.