diff --git a/esphome/config_helpers.py b/esphome/config_helpers.py
index 8bee3b3a52..c82c2b3dbe 100644
--- a/esphome/config_helpers.py
+++ b/esphome/config_helpers.py
@@ -105,6 +105,9 @@ def frameworks_for_platforms(platforms: Collection[str]) -> set[PlatformFramewor
     registry: deriving the framework set here means a platform added to the
     registry cannot validate and then fail at link on a filtered-out file.
     """
+    known = {pf.value[0].value for pf in PlatformFramework}
+    if unknown := set(platforms) - known:
+        raise ValueError(f"unknown platform(s): {sorted(unknown)}")
     return {pf for pf in PlatformFramework if pf.value[0].value in platforms}
 
 
diff --git a/tests/component_tests/bluetooth_proxy/test_platform_gates.py b/tests/component_tests/bluetooth_proxy/test_platform_gates.py
index 8e1e413ad0..a47dfd53fa 100644
--- a/tests/component_tests/bluetooth_proxy/test_platform_gates.py
+++ b/tests/component_tests/bluetooth_proxy/test_platform_gates.py
@@ -189,7 +189,7 @@ def test_hub_source_filter_covers_every_hub_platform() -> None:
     hub_frameworks = bluetooth_connection.SOURCE_FILE_FRAMEWORKS[
         "bluetooth_connection_hub.cpp"
     ]
-    assert expected <= hub_frameworks
+    assert expected == hub_frameworks
 
 
 def test_bluetooth_connection_auto_load_covers_its_includes() -> None: