diff --git a/Library/Homebrew/cmd/vendor-install.sh b/Library/Homebrew/cmd/vendor-install.sh
index 46f0c72f9d..fe7e26dd44 100644
--- a/Library/Homebrew/cmd/vendor-install.sh
+++ b/Library/Homebrew/cmd/vendor-install.sh
@@ -82,6 +82,15 @@ fetch() {
   elif [[ -x "$(which sha256sum)" ]]
   then
     sha="$(sha256sum "$CACHED_LOCATION" | cut -d' ' -f1)"
+  elif [[ -x "$(which ruby)" ]]
+  then
+    sha="$(ruby <<EOSCRIPT
+            require 'digest/sha2'
+            digest = Digest::SHA256.new
+            File.open('$CACHED_LOCATION', 'rb') { |f| digest.update(f.read) }
+            puts digest.hexdigest
+EOSCRIPT
+)"
   else
     odie "Cannot verify the checksum ('shasum' or 'sha256sum' not found)!"
   fi
diff --git a/Library/Homebrew/extend/pathname.rb b/Library/Homebrew/extend/pathname.rb
index c413e9e94b..93b1c720bd 100644
--- a/Library/Homebrew/extend/pathname.rb
+++ b/Library/Homebrew/extend/pathname.rb
@@ -322,7 +322,7 @@ class Pathname
 
   def sha256
     require "digest/sha2"
-    incremental_hash(Digest::SHA2)
+    incremental_hash(Digest::SHA256)
   end
 
   def verify_checksum(expected)