diff --git a/Library/Formula/simh.rb b/Library/Formula/simh.rb
index 5d19d08f6ac7..7bfd4b832a56 100644
--- a/Library/Formula/simh.rb
+++ b/Library/Formula/simh.rb
@@ -1,23 +1,23 @@
 require 'formula'
 
 class Simh < Formula
-  url 'http://simh.trailing-edge.com/sources/simhv38-1.zip'
-  version '3.8-1'
   homepage 'http://simh.trailing-edge.com/'
-  md5 'e15f65a82e21ea49e14b438326d93d5c'
+  url 'http://simh.trailing-edge.com/sources/simhv39-0.zip'
+  sha1 '1de3938f0dcb51d55b0e53aea8ae9769ccc57bdb'
+  version '3.9-0'
 
-  def install
-    ENV['OSTYPE'] = 'darwin'
-    mkdir 'BIN'
-    inreplace "makefile" do |s|
-      # Note: change_make_var! doesn't work for this makefile
-      s.gsub! "NETWORK_OPT = -DUSE_NETWORK -isystem /usr/local/include /usr/local/lib/libpcap.a",
-              "NETWORK_OPT = -DUSE_NETWORK -lpcap"
+  # After 3.9-0 the project moves to https://github.com/simh/simh
+  # It doesn't actually fail, but the makefile queries llvm-gcc -v --help a lot
+  # to determine what flags to throw.  It is simply not designed for clang.
+  # Remove at the next revision that will support clang (see github site).
+  fails_with :clang do
+    build 318
+    cause 'The program is closely tied to gcc & llvm-gcc in this revision.'
+  end
 
-      # Use our compiler & flags, and don't create dSYMs.
-      s.gsub! "CC = gcc -std=c99 -U__STRICT_ANSI__ -g $(OS_CCDEFS) -I .",
-              "CC = #{ENV.cc} #{ENV.cflags} -std=c99 -U__STRICT_ANSI__ $(OS_CCDEFS) -I ."
-    end
+  def install
+    inreplace 'makefile', 'GCC = gcc', "GCC = #{ENV.cc}"
+    inreplace 'makefile', 'CFLAGS_O = -O2', "CFLAGS_O = #{ENV.cflags}"
     system "make USE_NETWORK=1 all"
     bin.install Dir['BIN/*']
   end