diff --git a/build/common_compiler_flags.py b/build/common_compiler_flags.py
index a9e0822..67e5ac1 100644
--- a/build/common_compiler_flags.py
+++ b/build/common_compiler_flags.py
@@ -63,6 +63,9 @@ def generate(env):
     elif env["optimize"] == "debug":
         env.Append(CPPDEFINES=["OPT_DEBUG_ENABLED"])
 
+    if env["harden_memory"] == "fast":
+        env.Append(CPPDEFINES=["_GLIBCXX_ASSERTIONS", ("_LIBCPP_HARDENING_MODE", "_LIBCPP_HARDENING_MODE_FAST"), ("_MSVC_STL_HARDENING", 1)])
+
     # Set optimize and debug_symbols flags.
     # "custom" means do nothing and let users set their own optimization flags.
     if env.get("is_msvc", False):
diff --git a/tools/targets.py b/tools/targets.py
index 34044e9..1a562aa 100644
--- a/tools/targets.py
+++ b/tools/targets.py
@@ -59,6 +59,14 @@ def options(opts):
     )
     opts.Add(BoolVariable("debug_symbols", "Build with debugging symbols", True))
     opts.Add(BoolVariable("dev_build", "Developer build with dev-only debugging code (DEV_ENABLED)", False))
+    opts.Add(EnumVariable(
+            "harden_memory",
+            "Library memory hardening (by default inferred from 'dev_build')",
+            "auto",
+            ["auto", "none", "fast"],
+            ignorecase=2
+        )
+    )
 
 
 def exists(env):
@@ -89,6 +97,13 @@ def generate(env):
             opt_level = "speed"
         env["optimize"] = ARGUMENTS.get("optimize", opt_level)
 
+    if env["harden_memory"] == "auto":
+        if env.dev_build:
+            harden_level = "none"
+        else:
+            harden_level = "fast"
+        env["harden_memory"] = ARGUMENTS.get("harden_memory", harden_level)
+
     env["debug_symbols"] = get_cmdline_bool("debug_symbols", env.dev_build)
 
     if env.use_hot_reload: