diff --git a/ruby.spec b/ruby.spec
index 3f1a8ee..3d3d309 100644
--- a/ruby.spec
+++ b/ruby.spec
@@ -22,7 +22,7 @@
 %endif
 
 
-%global release 135
+%global release 137
 %{!?release_string:%define release_string %{?development_release:0.}%{release}%{?development_release:.%{development_release}}%{?dist}}
 
 # The RubyGems library has to stay out of Ruby directory tree, since the
@@ -199,6 +199,7 @@ BuildRequires: procps
 %{?with_hostname:BuildRequires: %{_bindir}/hostname}
 BuildRequires: multilib-rpm-config
 BuildRequires: gcc
+BuildRequires: make
 BuildRequires: zlib-devel
 
 # This package provides %%{_bindir}/ruby-mri therefore it is marked by this
@@ -218,6 +219,9 @@ Requires:   %{name}%{?_isa} = %{version}-%{release}
 # This would not be needed if ~50 packages depending on -devel used
 # --disable-gems
 Requires:   rubygems
+# Users need CFLAGS from /usr/lib/rpm/redhat/redhat-hardened-cc1
+# for building gems with binary extensions (rhbz#1905222).
+Recommends: redhat-rpm-config
 
 %description devel
 Header files and libraries for building an extension library for the
@@ -1285,6 +1289,13 @@ MSPECOPTS="$MSPECOPTS -P 'File.lchmod changes the file mode of the link and not
 
 
 %changelog
+* Tue Dec 15 16:26:46 CET 2020 Pavel Valena <pvalena@redhat.com> - 2.7.2-137
+- Add Recommends: redhat-rpm-config to devel subpackage.
+  Resolves: rhbz#1905222
+
+* Tue Nov 24 18:16:02 CET 2020 Vít Ondruch <vondruch@redhat.com> - 2.7.2-136
+- Add explicit `BR: make`.
+
 * Tue Oct 13 2020 Vít Ondruch <vondruch@redhat.com> - 2.7.2-135
 - Upgrade to Ruby 2.7.2.