diff --git a/Formula/clamav.rb b/Formula/clamav.rb
index 8beda6b32ba..aed4e78806d 100644
--- a/Formula/clamav.rb
+++ b/Formula/clamav.rb
@@ -1,14 +1,21 @@
-require 'formula'
+require "formula"
 
 class Clamav < Formula
-  homepage 'http://www.clamav.net/'
-  url 'https://downloads.sourceforge.net/clamav/0.98/clamav-0.98.1.tar.gz'
-  sha1 '9f04c0e81463c36f7e58d18f16d1b88f3332dcb8'
+  homepage "http://www.clamav.net/"
+  url "https://downloads.sourceforge.net/clamav/0.98/clamav-0.98.1.tar.gz"
+  sha1 "9f04c0e81463c36f7e58d18f16d1b88f3332dcb8"
 
-  skip_clean 'share'
+  skip_clean "share"
+
+  # Upstream patch for clang compatibility
+  # https://bugzilla.clamav.net/show_bug.cgi?id=10757
+  patch :p0 do
+    url "https://trac.macports.org/export/119480/trunk/dports/sysutils/clamav/files/patch-libclamav-LoopInfo.h.diff"
+    sha1 "647bfdd878a8db4b2a7af42c9887b1ae36c5e8de"
+  end
 
   def install
-    (share/'clamav').mkpath
+    (share/"clamav").mkpath
 
     args = %W{--disable-dependency-tracking
               --prefix=#{prefix}
@@ -18,6 +25,6 @@ class Clamav < Formula
     args << "--with-zlib=#{MacOS.sdk_path}/usr" unless MacOS::CLT.installed?
 
     system "./configure", *args
-    system "make install"
+    system "make", "install"
   end
 end