diff --git a/esphome/components/esp32/__init__.py b/esphome/components/esp32/__init__.py
index 5aeff91830..4f77258b2c 100644
--- a/esphome/components/esp32/__init__.py
+++ b/esphome/components/esp32/__init__.py
@@ -1816,8 +1816,11 @@ async def to_code(config):
                 Path(__file__).parent / "iram_fix.py.script",
             )
     else:
-        # Undo IDF's blanket -Werror so third-party libraries and user
-        # lambdas don't need a -Wno-error=<class> entry per warning class.
+        # Demote IDF's blanket -Werror to warnings so third-party libs
+        # and user lambdas don't need a -Wno-error=<class> per warning.
+        # The sdkconfig knob disables IDF's rewrite to -Werror=all (which
+        # can't be globally undone); -Wno-error then handles the demotion.
+        add_idf_sdkconfig_option("CONFIG_COMPILER_DISABLE_DEFAULT_ERRORS", False)
         cg.add_build_flag("-Wno-error")
         # -Wno- (not -Wno-error=): suppress entirely, too noisy on C++ aggregates
         cg.add_build_flag("-Wno-missing-field-initializers")