diff --git a/Tools/ardupilotwaf/boards.py b/Tools/ardupilotwaf/boards.py
index 75e98270bb..8b8747d670 100644
--- a/Tools/ardupilotwaf/boards.py
+++ b/Tools/ardupilotwaf/boards.py
@@ -122,6 +122,7 @@ class Board:
             '-Werror=parentheses',
             '-Werror=format-extra-args',
             '-Werror=ignored-qualifiers',
+            '-DARDUPILOT_BUILD',
         ]
 
         if cfg.options.scripting_checks:
@@ -205,6 +206,7 @@ class Board:
             '-Wfatal-errors',
             '-Wno-trigraphs',
             '-Werror=parentheses',
+            '-DARDUPILOT_BUILD',
         ]
 
         if 'clang++' in cfg.env.COMPILER_CXX:
@@ -249,6 +251,15 @@ class Board:
                     '-Werror=implicit-fallthrough',
                 ]
 
+        if cfg.options.Werror:
+            errors = ['-Werror',
+                      '-Werror=missing-declarations',
+                      '-Werror=float-equal',
+                      '-Werror=undef',
+                    ]
+            env.CFLAGS += errors
+            env.CXXFLAGS += errors
+
         if cfg.env.DEBUG:
             env.CXXFLAGS += [
                 '-g',
@@ -481,11 +492,6 @@ class chibios(Board):
             '-Wframe-larger-than=1300',
             '-fsingle-precision-constant',
             '-Wno-attributes',
-            '-Wno-error=double-promotion',
-            '-Wno-error=missing-declarations',
-            '-Wno-error=float-equal',
-            '-Wno-error=undef',
-            '-Wno-error=cpp',
             '-fno-exceptions',
             '-Wall',
             '-Wextra',
@@ -521,6 +527,15 @@ class chibios(Board):
             '-D__USE_CMSIS',
             '-Werror=deprecated-declarations'
         ]
+        if not cfg.options.Werror:
+            env.CFLAGS += [
+            '-Wno-error=double-promotion',
+            '-Wno-error=missing-declarations',
+            '-Wno-error=float-equal',
+            '-Wno-error=undef',
+            '-Wno-error=cpp',
+            ]
+
         env.CXXFLAGS += env.CFLAGS + [
             '-fno-rtti',
             '-fno-threadsafe-statics',
diff --git a/wscript b/wscript
index c420f3054f..8d160e4162 100644
--- a/wscript
+++ b/wscript
@@ -76,6 +76,11 @@ def options(opt):
         default=False,
         help='Configure as debug variant.')
 
+    g.add_option('--Werror',
+        action='store_true',
+        default=False,
+        help='build with -Werror.')
+    
     g.add_option('--toolchain',
         action='store',
         default=None,