diff --git a/config/external/icu/common/moz.build b/config/external/icu/common/moz.build
index b670c0622236..7477c99bf74c 100644
--- a/config/external/icu/common/moz.build
+++ b/config/external/icu/common/moz.build
@@ -8,6 +8,7 @@ Library("icuuc")
 FINAL_LIBRARY = "icu"
 
 DEFINES["U_COMMON_IMPLEMENTATION"] = True
+DEFINES["_LIBCPP_DISABLE_DEPRECATION_WARNINGS"] = True
 
 LOCAL_INCLUDES += ["/intl/icu/source/i18n"]
 
diff --git a/config/external/icu/i18n/moz.build b/config/external/icu/i18n/moz.build
index 098aa7843f91..890b04aaa7a8 100644
--- a/config/external/icu/i18n/moz.build
+++ b/config/external/icu/i18n/moz.build
@@ -8,6 +8,7 @@ Library("icui18n")
 FINAL_LIBRARY = "icu"
 
 DEFINES["U_I18N_IMPLEMENTATION"] = True
+DEFINES["_LIBCPP_DISABLE_DEPRECATION_WARNINGS"] = True
 
 LOCAL_INCLUDES += ["/intl/icu/source/common"]
 LOCAL_INCLUDES += ["/mfbt/double-conversion"]