diff --git a/assets/css/src/newsletter_editor/components/save.styl b/assets/css/src/newsletter_editor/components/save.styl
index d5bfb36f9e..8a31046605 100644
--- a/assets/css/src/newsletter_editor/components/save.styl
+++ b/assets/css/src/newsletter_editor/components/save.styl
@@ -38,9 +38,7 @@
       content: '\f142'
 
 .mailpoet_save_show_options_icon
-  width: auto
-  height: auto
-  line-height: auto
+  vertical-align: middle
 
   &::before
     content: '\f140'
diff --git a/assets/css/src/newsletter_editor/libraryOverrides.styl b/assets/css/src/newsletter_editor/libraryOverrides.styl
index 07643a72a8..78491b2929 100644
--- a/assets/css/src/newsletter_editor/libraryOverrides.styl
+++ b/assets/css/src/newsletter_editor/libraryOverrides.styl
@@ -133,3 +133,17 @@ body
 .wrap > .mailpoet_notice,
 .update-nag
   margin-left: 2px + 15px !important
+
+/* Make a button group */
+.mailpoet_button_group
+
+  .button:first-child
+    border-right: 0
+    border-top-right-radius: 0
+    border-bottom-right-radius: 0
+
+  .button:last-child
+    border-left: 0
+    border-top-left-radius: 0
+    border-bottom-left-radius: 0
+
diff --git a/views/newsletter/templates/blocks/automatedLatestContent/settings.hbs b/views/newsletter/templates/blocks/automatedLatestContent/settings.hbs
index 5ca668beab..0da041ae91 100644
--- a/views/newsletter/templates/blocks/automatedLatestContent/settings.hbs
+++ b/views/newsletter/templates/blocks/automatedLatestContent/settings.hbs
@@ -291,6 +291,6 @@
 </div>
 
 <div class="mailpoet_form_field">
-    <input type="button" class="mailpoet_button mailpoet_button_primary mailpoet_done_editing" value="<%= __('Done') %>" />
+    <input type="button" class="button button-primary mailpoet_done_editing" value="<%= __('Done') %>" />
 </div>
 
diff --git a/views/newsletter/templates/blocks/button/settings.hbs b/views/newsletter/templates/blocks/button/settings.hbs
index 6ea3eccb82..6ad613c702 100644
--- a/views/newsletter/templates/blocks/button/settings.hbs
+++ b/views/newsletter/templates/blocks/button/settings.hbs
@@ -101,11 +101,11 @@
 </div>
 {{#ifCond renderOptions.hideApplyToAll '!==' true}}
 <div class="mailpoet_form_field">
-    <input type="button" name="replace-all-button-styles" class="mailpoet_button mailpoet_button_full mailpoet_button_secondary mailpoet_field_button_replace_all_styles" value="<%= __('Apply styles to all buttons') %>" />
+    <input type="button" name="replace-all-button-styles" class="button button-secondary mailpoet_button_full mailpoet_field_button_replace_all_styles" value="<%= __('Apply styles to all buttons') %>" />
 </div>
 {{/ifCond}}
 
 <div class="mailpoet_form_field">
-    <input type="button" class="mailpoet_button mailpoet_button_primary mailpoet_done_editing" value="<%= __('Done') %>" />
+    <input type="button" class="button button-primary mailpoet_done_editing" value="<%= __('Done') %>" />
 </div>
 
diff --git a/views/newsletter/templates/blocks/container/settings.hbs b/views/newsletter/templates/blocks/container/settings.hbs
index 62e26f22fb..7f851afcbe 100644
--- a/views/newsletter/templates/blocks/container/settings.hbs
+++ b/views/newsletter/templates/blocks/container/settings.hbs
@@ -11,5 +11,5 @@
 <div class="mailpoet_container_columns_settings"></div>
 
 <div class="mailpoet_form_field">
-    <input type="button" class="mailpoet_button mailpoet_button_primary mailpoet_done_editing" value="<%= __('Done') %>" />
+    <input type="button" class="button button-primary mailpoet_done_editing" value="<%= __('Done') %>" />
 </div>
diff --git a/views/newsletter/templates/blocks/divider/settings.hbs b/views/newsletter/templates/blocks/divider/settings.hbs
index a3cc6a5500..474c725dc5 100644
--- a/views/newsletter/templates/blocks/divider/settings.hbs
+++ b/views/newsletter/templates/blocks/divider/settings.hbs
@@ -29,10 +29,10 @@
 </div>
 {{#ifCond renderOptions.hideApplyToAll '!==' true}}
 <div class="mailpoet_form_field">
-    <input type="button" name="apply-to-all-dividers" class="mailpoet_button mailpoet_button_full mailpoet_button_secondary mailpoet_button_divider_apply_to_all" value="<%= __('Apply to all dividers') %>" />
+    <input type="button" name="apply-to-all-dividers" class="button button-secondary mailpoet_button_full mailpoet_button_divider_apply_to_all" value="<%= __('Apply to all dividers') %>" />
 </div>
 {{/ifCond}}
 
 <div class="mailpoet_form_field">
-    <input type="button" class="mailpoet_button mailpoet_button_primary mailpoet_done_editing" value="<%= __('Done') %>" />
+    <input type="button" class="button button-primary mailpoet_done_editing" value="<%= __('Done') %>" />
 </div>
diff --git a/views/newsletter/templates/blocks/footer/settings.hbs b/views/newsletter/templates/blocks/footer/settings.hbs
index 3ef7cbe43d..68951bd055 100644
--- a/views/newsletter/templates/blocks/footer/settings.hbs
+++ b/views/newsletter/templates/blocks/footer/settings.hbs
@@ -56,5 +56,5 @@
 </div>
 
 <div class="mailpoet_form_field">
-    <input type="button" class="mailpoet_button mailpoet_button_primary mailpoet_done_editing" value="<%= __('Done') %>" />
+    <input type="button" class="button button-primary mailpoet_done_editing" value="<%= __('Done') %>" />
 </div>
diff --git a/views/newsletter/templates/blocks/header/settings.hbs b/views/newsletter/templates/blocks/header/settings.hbs
index b16b780542..55439dd4bb 100644
--- a/views/newsletter/templates/blocks/header/settings.hbs
+++ b/views/newsletter/templates/blocks/header/settings.hbs
@@ -56,5 +56,5 @@
 </div>
 
 <div class="mailpoet_form_field">
-    <input type="button" class="mailpoet_button mailpoet_button_primary mailpoet_done_editing" value="<%= __('Done') %>" />
+    <input type="button" class="button button-primary mailpoet_done_editing" value="<%= __('Done') %>" />
 </div>
diff --git a/views/newsletter/templates/blocks/image/settings.hbs b/views/newsletter/templates/blocks/image/settings.hbs
index 49912a221e..09df68bb27 100644
--- a/views/newsletter/templates/blocks/image/settings.hbs
+++ b/views/newsletter/templates/blocks/image/settings.hbs
@@ -33,9 +33,9 @@
 </div>
 <hr />
 <div class="mailpoet_form_field">
-    <input type="button" name="select-another-image" class="mailpoet_button mailpoet_button_full mailpoet_button_secondary mailpoet_field_image_select_another_image" value="<%= __('Select another image') %>" />
+    <input type="button" name="select-another-image" class="button button-secondary mailpoet_button_full mailpoet_field_image_select_another_image" value="<%= __('Select another image') %>" />
 </div>
 
 <div class="mailpoet_form_field">
-    <input type="button" class="mailpoet_button mailpoet_button_primary mailpoet_done_editing" value="<%= __('Done') %>" />
+    <input type="button" class="button button-primary mailpoet_done_editing" value="<%= __('Done') %>" />
 </div>
diff --git a/views/newsletter/templates/blocks/posts/settings.hbs b/views/newsletter/templates/blocks/posts/settings.hbs
index 6223f2b2cd..66222db2fc 100644
--- a/views/newsletter/templates/blocks/posts/settings.hbs
+++ b/views/newsletter/templates/blocks/posts/settings.hbs
@@ -6,5 +6,5 @@
       <a href="javascript:;" class="mailpoet_settings_posts_show_post_selection mailpoet_hidden"><%= __('Back to selection') %></a>
       <a href="javascript:;" class="mailpoet_settings_posts_show_display_options"><%= __('Display options') %></a>
   </div>
-  <input type="button" class="mailpoet_button mailpoet_button_primary mailpoet_settings_posts_insert_selected" value="<%= __('Insert selected') %>" />
+  <input type="button" class="button button-primary mailpoet_settings_posts_insert_selected" value="<%= __('Insert selected') %>" />
 </div>
diff --git a/views/newsletter/templates/blocks/social/settings.hbs b/views/newsletter/templates/blocks/social/settings.hbs
index c1e1127331..82d82c2d49 100644
--- a/views/newsletter/templates/blocks/social/settings.hbs
+++ b/views/newsletter/templates/blocks/social/settings.hbs
@@ -3,5 +3,5 @@
 <h3><%= __('Styles') %></h3>
 <div id="mailpoet_social_icons_styles"></div>
 <div class="mailpoet_form_field">
-  <input type="button" class="mailpoet_button mailpoet_button_primary mailpoet_done_editing" value="<%= __('Done') %>" />
+  <input type="button" class="button button-primary mailpoet_done_editing" value="<%= __('Done') %>" />
 </div>
diff --git a/views/newsletter/templates/blocks/social/settingsIconSelector.hbs b/views/newsletter/templates/blocks/social/settingsIconSelector.hbs
index 8ea7d70a63..a9ad6a2198 100644
--- a/views/newsletter/templates/blocks/social/settingsIconSelector.hbs
+++ b/views/newsletter/templates/blocks/social/settingsIconSelector.hbs
@@ -1,2 +1,2 @@
 <div id="mailpoet_social_icon_selector_contents"></div>
-<input type="button" class="mailpoet_button mailpoet_button_full mailpoet_button_secondary mailpoet_add_social_icon" value="<%= __('Add another social network') %>" />
+<input type="button" class="button button-secondary mailpoet_button_full mailpoet_add_social_icon" value="<%= __('Add another social network') %>" />
diff --git a/views/newsletter/templates/blocks/spacer/settings.hbs b/views/newsletter/templates/blocks/spacer/settings.hbs
index ec3a6eb7e1..cb4b681997 100644
--- a/views/newsletter/templates/blocks/spacer/settings.hbs
+++ b/views/newsletter/templates/blocks/spacer/settings.hbs
@@ -7,5 +7,5 @@
 </div>
 
 <div class="mailpoet_form_field">
-    <input type="button" class="mailpoet_button mailpoet_button_primary mailpoet_done_editing" value="<%= __('Done') %>" />
+    <input type="button" class="button button-primary mailpoet_done_editing" value="<%= __('Done') %>" />
 </div>
diff --git a/views/newsletter/templates/components/save.hbs b/views/newsletter/templates/components/save.hbs
index 3a29ca9cc2..75dce6d4e9 100644
--- a/views/newsletter/templates/components/save.hbs
+++ b/views/newsletter/templates/components/save.hbs
@@ -1,8 +1,8 @@
 <div class="mailpoet_save_wrapper">
     <div class="mailpoet_button_group">
-        <input type="button" name="save" value="<%= __('Save') %>" class="mailpoet_button mailpoet_button_primary mailpoet_save_button" /><button class="mailpoet_button mailpoet_button_primary mailpoet_save_show_options" ><span class="dashicons mailpoet_save_show_options_icon"></span></button>
+        <input type="button" name="save" value="<%= __('Save') %>" class="button button-primary mailpoet_save_button" /><button class="button button-primary mailpoet_save_show_options" ><span class="dashicons mailpoet_save_show_options_icon"></span></button>
     </div>
-    <input type="button" name="next" value="<%= __('Next') %>" class="mailpoet_button mailpoet_button_primary mailpoet_save_next" />
+    <input type="button" name="next" value="<%= __('Next') %>" class="button button-primary mailpoet_save_next" />
     <span class="mailpoet_save_error"></span>
     <div class="mailpoet_editor_last_saved mailpoet_hidden"><%= __('Autosaved') %> <span class="mailpoet_autosaved_at"></span></div>
     <br />
@@ -15,12 +15,12 @@
         <p><b class="mailpoet_save_as_template_title"><%= __('Save as template') %></b></p>
         <p><input type="text" name="template_name" value="" placeholder="<%= __('Insert template name') %>" class="mailpoet_input mailpoet_save_as_template_name" /></p>
         <p><input type="text" name="template_description" value="" placeholder="<%= __('Insert template description') %>" class="mailpoet_input mailpoet_save_as_template_description" /></p>
-        <p><input type="button" name="save_as_template" value="<%= __('Save as template') %>" class="mailpoet_button mailpoet_button_full mailpoet_button_primary mailpoet_save_as_template" /></p>
+        <p><input type="button" name="save_as_template" value="<%= __('Save as template') %>" class="button button-primary mailpoet_button_full mailpoet_save_as_template" /></p>
     </div>
     <div class="mailpoet_export_template_container mailpoet_hidden">
         <p><b class="mailpoet_export_template_title"><%= __('Export template') %></b></p>
         <p><input type="text" name="export_template_name" value="" placeholder="<%= __('Template name') %>" class="mailpoet_input mailpoet_export_template_name" /></p>
         <p><input type="text" name="export_template_description" value="" placeholder="<%= __('Template description') %>" class="mailpoet_input mailpoet_export_template_description" /></p>
-        <p><input type="button" name="export_template" value="<%= __('Export template') %>" class="mailpoet_button mailpoet_button_full mailpoet_button_primary mailpoet_export_template" /></p>
+        <p><input type="button" name="export_template" value="<%= __('Export template') %>" class="button button-primary mailpoet_button_full mailpoet_export_template" /></p>
     </div>
 </div>
diff --git a/views/newsletter/templates/components/sidebar/preview.hbs b/views/newsletter/templates/components/sidebar/preview.hbs
index 98aa53f20d..794685493f 100644
--- a/views/newsletter/templates/components/sidebar/preview.hbs
+++ b/views/newsletter/templates/components/sidebar/preview.hbs
@@ -9,10 +9,10 @@
     </div>
 
     <div class="mailpoet_form_field">
-        <input type="button" id="mailpoet_send_preview" class="mailpoet_button mailpoet_button_full mailpoet_button_primary" value="<%= __('Send preview') %>" />
+        <input type="button" id="mailpoet_send_preview" class="button button-primary mailpoet_button_full" value="<%= __('Send preview') %>" />
     </div>
 
     <hr class="mailpoet_separator" />
 
-    <input type="button" name="preview" class="mailpoet_button mailpoet_button_full mailpoet_button_primary mailpoet_show_preview" value="<%= __('View in browser') %>" />
+    <input type="button" name="preview" class="button button-primary mailpoet_button_full mailpoet_show_preview" value="<%= __('View in browser') %>" />
 </div>