diff --git a/pkgs/ffigen/CHANGELOG.md b/pkgs/ffigen/CHANGELOG.md
index 2058fce29..400332646 100644
--- a/pkgs/ffigen/CHANGELOG.md
+++ b/pkgs/ffigen/CHANGELOG.md
@@ -5,6 +5,7 @@
   `ffi-native` option.
 - Add `retainAndReturnPointer` method to ObjC objects and blocks, and add
   `castFromPointer` method to blocks.
+- Add `-Wno-nullability-completeness` as default compiler option for MacOS.
 
 ## 11.0.0
 
diff --git a/pkgs/ffigen/example/libclang-example/config.yaml b/pkgs/ffigen/example/libclang-example/config.yaml
index 6b3db356d..7e56f14c5 100644
--- a/pkgs/ffigen/example/libclang-example/config.yaml
+++ b/pkgs/ffigen/example/libclang-example/config.yaml
@@ -22,7 +22,6 @@ headers:
 compiler-opts:
   - '-I../../third_party/libclang/include'
   - '-I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/'
-  - '-Wno-nullability-completeness'
 functions:
   include:
     - 'clang_.*' # Can be a regexp, '.' matches any character.
diff --git a/pkgs/ffigen/lib/src/config_provider/config_types.dart b/pkgs/ffigen/lib/src/config_provider/config_types.dart
index ce6805122..7bec4928e 100644
--- a/pkgs/ffigen/lib/src/config_provider/config_types.dart
+++ b/pkgs/ffigen/lib/src/config_provider/config_types.dart
@@ -347,11 +347,11 @@ class CompilerOptsAuto {
 
   /// Extracts compiler options based on OS and config.
   List<String> extractCompilerOpts() {
-    if (Platform.isMacOS && macIncludeStdLib) {
-      return getCStandardLibraryHeadersForMac();
-    }
-
-    return [];
+    return [
+      if (Platform.isMacOS && macIncludeStdLib)
+        ...getCStandardLibraryHeadersForMac(),
+      if (Platform.isMacOS) '-Wno-nullability-completeness',
+    ];
   }
 }
 
diff --git a/pkgs/ffigen/test/config_tests/compiler_opts_test.dart b/pkgs/ffigen/test/config_tests/compiler_opts_test.dart
index 0b711acd6..422232d84 100644
--- a/pkgs/ffigen/test/config_tests/compiler_opts_test.dart
+++ b/pkgs/ffigen/test/config_tests/compiler_opts_test.dart
@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'dart:io';
+
 import 'package:ffigen/ffigen.dart';
 import 'package:ffigen/src/config_provider/spec_utils.dart';
 import 'package:ffigen/src/strings.dart' as strings;
@@ -40,7 +42,12 @@ ${strings.compilerOptsAuto}:
   ${strings.macos}:
     ${strings.includeCStdLib}: false
         ''');
-      expect(config.compilerOpts.isEmpty, true);
+      expect(
+        config.compilerOpts,
+        equals([
+          if (Platform.isMacOS) '-Wno-nullability-completeness',
+        ]),
+      );
     });
   });
 }
diff --git a/pkgs/ffigen/test/native_test/config.yaml b/pkgs/ffigen/test/native_test/config.yaml
index 3942f6f26..5066f4094 100644
--- a/pkgs/ffigen/test/native_test/config.yaml
+++ b/pkgs/ffigen/test/native_test/config.yaml
@@ -15,7 +15,6 @@ headers:
   include-directives:
     - '**native_test.c'
 
-compiler-opts: '-Wno-nullability-completeness'
 preamble: |
   // ignore_for_file: camel_case_types, non_constant_identifier_names
 
diff --git a/pkgs/ffigen/tool/libclang_config.yaml b/pkgs/ffigen/tool/libclang_config.yaml
index 7343442a5..46e373334 100644
--- a/pkgs/ffigen/tool/libclang_config.yaml
+++ b/pkgs/ffigen/tool/libclang_config.yaml
@@ -16,7 +16,6 @@ description: Holds bindings to LibClang.
 output: '../lib/src/header_parser/clang_bindings/clang_bindings.dart'
 compiler-opts:
   - '-Ithird_party/libclang/include'
-  - '-Wno-nullability-completeness'
 headers:
   entry-points:
     - '../third_party/libclang/include/clang-c/Index.h'