diff --git a/dependencies.yml b/dependencies.yml
index 25b818954f..bb07a276e7 100644
--- a/dependencies.yml
+++ b/dependencies.yml
@@ -9,8 +9,8 @@ libxslt:
   # sha-256 hash provided in https://download.gnome.org/sources/libxslt/1.1/libxslt-1.1.37.sha256sum
 
 zlib:
-  version: "1.2.12"
-  sha256: "91844808532e5ce316b3c010929493c0244f3d37593afd6de04f71821d5136d9"
+  version: "1.2.13"
+  sha256: "b3a24de97a8fdbc835b9833169501030b8977031bcb54b3b3ac13740f846ab30"
   # SHA-256 hash provided on http://zlib.net/
 
 libiconv:
diff --git a/ext/nokogiri/extconf.rb b/ext/nokogiri/extconf.rb
index b0c808d7fa..3000148418 100644
--- a/ext/nokogiri/extconf.rb
+++ b/ext/nokogiri/extconf.rb
@@ -712,9 +712,17 @@ def install
       else
         class << recipe
           def configure
-            cflags = concat_flags(ENV["CFLAGS"], "-fPIC", "-g")
-            execute("configure",
-              ["env", "CHOST=#{host}", "CFLAGS=#{cflags}", "./configure", "--static", configure_prefix])
+            env = {}
+            env["CFLAGS"] = concat_flags(ENV["CFLAGS"], "-fPIC", "-g")
+            env["CHOST"] = host
+            execute("configure", ["./configure", "--static", configure_prefix], { env: env })
+            if darwin?
+              # needed as of zlib 1.2.13
+              Dir.chdir(work_path) do
+                makefile = File.read("Makefile").gsub(/^AR=.*$/, "AR=#{host}-libtool")
+                File.open("Makefile", "w") { |m| m.write(makefile) }
+              end
+            end
           end
         end
       end