diff --git a/pkgs/development/interpreters/ruby/default.nix b/pkgs/development/interpreters/ruby/default.nix
index 363397c70dca..b7e0338b2d07 100644
--- a/pkgs/development/interpreters/ruby/default.nix
+++ b/pkgs/development/interpreters/ruby/default.nix
@@ -237,13 +237,9 @@ let
           ++ lib.optional stdenv.cc.isGNU "CFLAGS=-O3"
           ++ [
           ]
-          ++ ops stdenv.hostPlatform.isDarwin [
-            # on darwin, we have /usr/include/tk.h -- so the configure script detects
-            # that tk is installed
-            "--with-out-ext=tk"
-            # on yosemite, "generating encdb.h" will hang for a very long time without this flag
-            "--with-setjmp-type=setjmp"
-          ]
+          # on darwin, we have /usr/include/tk.h -- so the configure script detects
+          # that tk is installed
+          ++ lib.optional stdenv.hostPlatform.isDarwin "--with-out-ext=tk"
           ++ ops stdenv.hostPlatform.isFreeBSD [
             "rb_cv_gnu_qsort_r=no"
             "rb_cv_bsd_qsort_r=yes"