diff --git a/pkgs/development/interpreters/ruby/default.nix b/pkgs/development/interpreters/ruby/default.nix
index f09db23faa80..9091d247d65a 100644
--- a/pkgs/development/interpreters/ruby/default.nix
+++ b/pkgs/development/interpreters/ruby/default.nix
@@ -222,10 +222,10 @@ in {
   };
 
   ruby_2_5 = generic {
-    version = rubyVersion "2" "5" "5" "";
+    version = rubyVersion "2" "5" "6" "";
     sha256 = {
-      src = "0k2in88jymqh727s88yjsv7wrqs2hdj9h2w9zh2bmrj0ygylba98";
-      git = "0l7b7xv48gvvlqs27gghfi645qvc1nwiz8ym4j8w100rzzzfy6zz";
+      src = "19xy6rf138ys4qycv0ibsycqwbjmf1j6iv9plw9cs81hcxnd0zhx";
+      git = "067gyy7149m6vk9dfyx22mghm2gbgy7snfa7df4ddrvr1pqffqmz";
     };
   };
 
diff --git a/pkgs/development/interpreters/ruby/patchsets.nix b/pkgs/development/interpreters/ruby/patchsets.nix
index d1a5d4c2d022..429e5e210ed3 100644
--- a/pkgs/development/interpreters/ruby/patchsets.nix
+++ b/pkgs/development/interpreters/ruby/patchsets.nix
@@ -11,7 +11,7 @@ rec {
     "${patchSet}/patches/ruby/2.4/head/railsexpress/02-improve-gc-stats.patch"
     "${patchSet}/patches/ruby/2.4/head/railsexpress/03-display-more-detailed-stack-trace.patch"
   ];
-  "2.5.5" = ops useRailsExpress [
+  "2.5.6" = ops useRailsExpress [
     "${patchSet}/patches/ruby/2.5/head/railsexpress/01-fix-broken-tests-caused-by-ad.patch"
     "${patchSet}/patches/ruby/2.5/head/railsexpress/02-improve-gc-stats.patch"
     "${patchSet}/patches/ruby/2.5/head/railsexpress/03-more-detailed-stacktrace.patch"