diff --git a/python/servo/command_base.py b/python/servo/command_base.py
index e6b3ec7908b..20c02852d8a 100644
--- a/python/servo/command_base.py
+++ b/python/servo/command_base.py
@@ -321,6 +321,7 @@ class CommandBase(object):
         self.config.setdefault("build", {})
         self.config["build"].setdefault("android", False)
         self.config["build"].setdefault("mode", "")
+        self.config["build"].setdefault("debug-assertions", False)
         self.config["build"].setdefault("debug-mozjs", False)
         self.config["build"].setdefault("ccache", "")
         self.config["build"].setdefault("rustflags", "")
@@ -933,7 +934,7 @@ install them, let us know by filing a bug!")
             features.append("webgl-backtrace")
         if self.config["build"]["dom-backtrace"]:
             features.append("dom-backtrace")
-        if with_debug_assertions:
+        if with_debug_assertions or self.config["build"]["debug-assertions"]:
             env['RUSTFLAGS'] = env.get('RUSTFLAGS', "") + " -C debug_assertions"
 
         assert "--features" not in cargo_args
diff --git a/servobuild.example b/servobuild.example
index 2070da1a59c..a115f69f055 100644
--- a/servobuild.example
+++ b/servobuild.example
@@ -29,6 +29,9 @@ rustc-with-gold = true
 # Set "android = true" or use `mach build --android` to build the Android app.
 android = false
 
+# Enable `debug_assert!` macros in release mode
+debug-assertions = false
+
 # Set "debug-mozjs" or use `mach build --debug-mozjs` to build a debug spidermonkey.
 debug-mozjs = false