diff --git a/scripts/fbt/appmanifest.py b/scripts/fbt/appmanifest.py
index eb265cee8..820f5a8c5 100644
--- a/scripts/fbt/appmanifest.py
+++ b/scripts/fbt/appmanifest.py
@@ -1,7 +1,8 @@
 import os
+import re
 from dataclasses import dataclass, field
 from enum import Enum
-from typing import Callable, List, Optional, Tuple, Union
+from typing import Callable, ClassVar, List, Optional, Tuple, Union
 
 
 class FlipperManifestException(Exception):
@@ -23,6 +24,8 @@ class FlipperAppType(Enum):
 
 @dataclass
 class FlipperApplication:
+    APP_ID_REGEX: ClassVar[re.Pattern] = re.compile(r"^[a-z0-9_]+$")
+
     @dataclass
     class ExternallyBuiltFile:
         path: str
@@ -84,6 +87,10 @@ class FlipperApplication:
     def __post_init__(self):
         if self.apptype == FlipperAppType.PLUGIN:
             self.stack_size = 0
+        if not self.APP_ID_REGEX.match(self.appid):
+            raise FlipperManifestException(
+                f"Invalid appid '{self.appid}'. Must match regex '{self.APP_ID_REGEX}'"
+            )
         if isinstance(self.fap_version, str):
             try:
                 self.fap_version = tuple(int(v) for v in self.fap_version.split("."))
diff --git a/scripts/ufbt/SConstruct b/scripts/ufbt/SConstruct
index d72de380c..a1acd270a 100644
--- a/scripts/ufbt/SConstruct
+++ b/scripts/ufbt/SConstruct
@@ -75,7 +75,7 @@ from fbt.util import (
     wrap_tempfile,
     path_as_posix,
 )
-from fbt.appmanifest import FlipperAppType
+from fbt.appmanifest import FlipperAppType, FlipperApplication
 from fbt.sdk.cache import SdkCache
 
 # Base environment with all tools loaded from SDK
@@ -410,6 +410,12 @@ dist_env.Alias("vscode_dist", vscode_dist)
 # Creating app from base template
 
 dist_env.SetDefault(FBT_APPID=appenv.subst("$APPID") or "template")
+if fbt_appid := dist_env.subst("$FBT_APPID"):
+    if not FlipperApplication.APP_ID_REGEX.match(fbt_appid):
+        raise UserError(
+            f"Invalid app id '{fbt_appid}'. App id must match {FlipperApplication.APP_ID_REGEX.pattern}"
+        )
+
 app_template_dir = project_template_dir.Dir("app_template")
 app_template_dist = []
 for template_file in app_template_dir.glob("*"):