diff --git a/Formula/dcmtk.rb b/Formula/dcmtk.rb
index 89b5a9febc..5c146106ba 100644
--- a/Formula/dcmtk.rb
+++ b/Formula/dcmtk.rb
@@ -26,8 +26,6 @@ class Dcmtk < Formula
   depends_on "homebrew/dupes/libiconv" => :optional
 
   def install
-    ENV.m64 if MacOS.prefer_64_bit?
-
     args = std_cmake_args
     args << "-DDCMTK_WITH_OPENSSL=YES"
     args << "-DDCMTK_WITH_DOXYGEN=YES" if build.with? "docs"