diff --git a/Formula/erlang@21.rb b/Formula/erlang@21.rb
index 307182439c..0b3b61f76b 100644
--- a/Formula/erlang@21.rb
+++ b/Formula/erlang@21.rb
@@ -34,6 +34,10 @@ class ErlangAT21 < Formula
   end
 
   def install
+    # Work around Xcode 11 clang bug
+    # https://bitbucket.org/multicoreware/x265/issues/514/wrong-code-generated-on-macos-1015
+    ENV.append_to_cflags "-fno-stack-check" if DevelopmentTools.clang_build_version >= 1010
+
     # Unset these so that building wx, kernel, compiler and
     # other modules doesn't fail with an unintelligable error.
     %w[LIBS FLAGS AFLAGS ZFLAGS].each { |k| ENV.delete("ERL_#{k}") }