diff --git a/CHANGELOG.md b/CHANGELOG.md
index b5d375ea..a5a048e4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+## 7.1.4
+
+* Allow Rails 7.0
+* Wice::Columns#add_css_class does not update the value given
+to the :class option of Wice::GridRenderer#column method.
+
 ## 7.1.3
 
 * Fixes [the bug](https://github.com/leikind/wice_grid/issues/395).
diff --git a/Gemfile.lock b/Gemfile.lock
index e52422ba..ff489be1 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -16,11 +16,11 @@ GIT
 PATH
   remote: .
   specs:
-    wice_grid (7.1.3)
+    wice_grid (7.1.4)
       coffee-rails (>= 5.0.0)
       jquery-rails
       kaminari
-      rails (~> 7.1)
+      rails (~> 7.0)
 
 GEM
   remote: https://rubygems.org/
diff --git a/lib/wice/columns.rb b/lib/wice/columns.rb
index 1a2fe2b1..fb790aa8 100644
--- a/lib/wice/columns.rb
+++ b/lib/wice/columns.rb
@@ -146,7 +146,7 @@ def add_css_class(klass_value) #:nodoc:
         if html[:class].nil?
           html[:class] = klass_value
         else
-          html[:class] << ' ' unless html[:class].empty?
+          html[:class] += ' ' unless html[:class].empty?
           html[:class] << klass_value
         end
       end
diff --git a/wice_grid.gemspec b/wice_grid.gemspec
index 2d030427..a3b091fc 100644
--- a/wice_grid.gemspec
+++ b/wice_grid.gemspec
@@ -1,6 +1,6 @@
 Gem::Specification.new do |s|
   s.name          = 'wice_grid'
-  s.version       = '7.1.3'
+  s.version       = '7.1.4'
   s.authors       = ['Yuri Leikind, Dimitri Kulk, and contributors']
   s.email         = ['dim.kulk@gmail.com']
   s.homepage      = 'https://github.com/leikind/wice_grid'
@@ -15,7 +15,7 @@ Gem::Specification.new do |s|
   s.require_paths = ['lib']
   s.date          = `date +%Y-%m-%d`
 
-  s.add_dependency 'rails', '~> 7.1'
+  s.add_dependency 'rails', '~> 7.0'
   s.add_dependency 'kaminari'
   s.add_dependency 'coffee-rails', '>= 5.0.0'
   s.add_dependency 'jquery-rails'