diff --git a/theme/clean/classes/core_renderer.php b/theme/clean/classes/core_renderer.php
index 14f8eeb900e..ff09b25e5e5 100644
--- a/theme/clean/classes/core_renderer.php
+++ b/theme/clean/classes/core_renderer.php
@@ -56,7 +56,8 @@ class theme_clean_core_renderer extends theme_bootstrapbase_core_renderer {
 
         // Only render the logo if we're on the front page or login page
         // and the theme has a logo.
-        if ($headinglevel == 1 && !empty($this->page->theme->settings->logo)) {
+        $logo = $this->get_logo_url();
+        if ($headinglevel == 1 && !empty($logo)) {
             if ($PAGE->pagelayout == 'frontpage' || $PAGE->pagelayout == 'login') {
                 return true;
             }
@@ -76,11 +77,11 @@ class theme_clean_core_renderer extends theme_bootstrapbase_core_renderer {
     public function navbar_home($returnlink = true) {
         global $CFG;
 
-        if ($this->should_render_logo() || empty($this->page->theme->settings->smalllogo)) {
+        $imageurl = $this->get_compact_logo_url(null, 35);
+        if ($this->should_render_logo() || empty($imageurl)) {
             // If there is no small logo we always show the site name.
             return $this->get_home_ref($returnlink);
         }
-        $imageurl = $this->page->theme->setting_file_url('smalllogo', 'smalllogo');
         $image = html_writer::img($imageurl, get_string('sitelogo', 'theme_' . $this->page->theme->name),
             array('class' => 'small-logo'));
 
@@ -118,4 +119,37 @@ class theme_clean_core_renderer extends theme_bootstrapbase_core_renderer {
 
         return html_writer::tag('span', $sitename, array('class' => 'brand'));
     }
+
+    /**
+     * Return the theme logo URL, else the site's logo URL, if any.
+     *
+     * Note that maximum sizes are not applied to the theme logo.
+     *
+     * @param int $maxwidth The maximum width, or null when the maximum width does not matter.
+     * @param int $maxheight The maximum height, or null when the maximum height does not matter.
+     * @return moodle_url|false
+     */
+    public function get_logo_url($maxwidth = null, $maxheight = 100) {
+        if (!empty($this->page->theme->settings->logo)) {
+            return $this->page->theme->setting_file_url('logo', 'logo');
+        }
+        return parent::get_logo_url($maxwidth, $maxheight);
+    }
+
+    /**
+     * Return the theme's compact logo URL, else the site's compact logo URL, if any.
+     *
+     * Note that maximum sizes are not applied to the theme logo.
+     *
+     * @param int $maxwidth The maximum width, or null when the maximum width does not matter.
+     * @param int $maxheight The maximum height, or null when the maximum height does not matter.
+     * @return moodle_url|false
+     */
+    public function get_compact_logo_url($maxwidth = 100, $maxheight = 100) {
+        if (!empty($this->page->theme->settings->smalllogo)) {
+            return $this->page->theme->setting_file_url('smalllogo', 'smalllogo');
+        }
+        return parent::get_compact_logo_url($maxwidth, $maxheight);
+    }
+
 }
diff --git a/theme/clean/lang/en/theme_clean.php b/theme/clean/lang/en/theme_clean.php
index 97c6cc13451..45aa332f224 100644
--- a/theme/clean/lang/en/theme_clean.php
+++ b/theme/clean/lang/en/theme_clean.php
@@ -57,7 +57,7 @@ $string['invert'] = 'Invert navbar';
 $string['invertdesc'] = 'Swaps text and background for the navbar at the top of the page between black and white.';
 
 $string['logo'] = 'Logo';
-$string['logodesc'] = 'The logo is only displayed in the header of the front page and login page.<br /> If the height of your logo is more than 75px add div.logo {height: 100px;} to the Custom CSS box below, amending accordingly if the height is other than 100px.';
+$string['logodesc'] = 'The logo is only displayed in the header of the front page and login page.<br /> If the height of your logo is more than 75px add div.logo {height: 100px;} to the Custom CSS box below, amending accordingly if the height is other than 100px. Note that when not set, the logo from \'Appearance > Branding\' will be used.';
 
 $string['pluginname'] = 'Clean';
 
@@ -68,4 +68,4 @@ $string['sitelogo'] = 'Site logo';
 $string['sitename'] = 'Display site name along with small logo';
 $string['sitenamedesc'] = 'If there is no small logo, the site name is always displayed in the navigation bar. If a small logo is set, it may be displayed with or without the site name.';
 $string['smalllogo'] = 'Small logo';
-$string['smalllogodesc'] = 'The small logo is displayed in the navigation bar. If there is a header logo for the front page and login page, the small logo is not displayed on these pages.';
+$string['smalllogodesc'] = 'The small logo is displayed in the navigation bar. If there is a header logo for the front page and login page, the small logo is not displayed on these pages. Note that when not set, the compact logo from \'Appearance > Branding\' will be used.';
diff --git a/theme/clean/lib.php b/theme/clean/lib.php
index 889c9aea064..f7a5202c7e6 100644
--- a/theme/clean/lib.php
+++ b/theme/clean/lib.php
@@ -38,9 +38,10 @@
  * @return string The parsed CSS The parsed CSS.
  */
 function theme_clean_process_css($css, $theme) {
+    global $OUTPUT;
 
     // Set the background image for the logo.
-    $logo = $theme->setting_file_url('logo', 'logo');
+    $logo = $OUTPUT->get_logo_url(null, 75);
     $css = theme_clean_set_logo($css, $logo);
 
     // Set custom CSS.
diff --git a/theme/more/lang/en/theme_more.php b/theme/more/lang/en/theme_more.php
index acd7bb6ac8e..e5fa4ca0111 100644
--- a/theme/more/lang/en/theme_more.php
+++ b/theme/more/lang/en/theme_more.php
@@ -64,7 +64,7 @@ $string['invertdesc'] = 'Swaps text and background for the navbar at the top of
 $string['linkcolor'] = 'Link colour';
 $string['linkcolor_desc'] = 'The colour of the links.';
 $string['logo'] = 'Logo';
-$string['logodesc'] = 'The logo is only displayed in the header of the front page and login page.<br /> If the height of your logo is more than 75px add div.logo {height: 100px;} to the Custom CSS box below, amending accordingly if the height is other than 100px.';
+$string['logodesc'] = 'The logo is only displayed in the header of the front page and login page.<br /> If the height of your logo is more than 75px add div.logo {height: 100px;} to the Custom CSS box below, amending accordingly if the height is other than 100px. Note that when not set, the logo from \'Appearance > Branding\' will be used.';
 
 $string['pluginname'] = 'More';
 
@@ -76,7 +76,7 @@ $string['sitelogo'] = 'Site logo';
 $string['sitename'] = 'Display site name along with small logo';
 $string['sitenamedesc'] = 'If there is no small logo, the site name is always displayed in the navigation bar. If a small logo is set, it may be displayed with or without the site name.';
 $string['smalllogo'] = 'Small logo';
-$string['smalllogodesc'] = 'The small logo is displayed in the navigation bar. If there is a header logo for the front page and login page, the small logo is not displayed on these pages.';
+$string['smalllogodesc'] = 'The small logo is displayed in the navigation bar. If there is a header logo for the front page and login page, the small logo is not displayed on these pages. Note that when not set, the compact logo from \'Appearance > Branding\' will be used.';
 $string['textcolor'] = 'Text colour';
 $string['textcolor_desc'] = 'The colour of the text.';
 
diff --git a/theme/more/lib.php b/theme/more/lib.php
index b1f6f45b66d..0162903e511 100644
--- a/theme/more/lib.php
+++ b/theme/more/lib.php
@@ -99,9 +99,10 @@ function theme_more_less_variables($theme) {
  * @return string The parsed CSS The parsed CSS.
  */
 function theme_more_process_css($css, $theme) {
+    global $OUTPUT;
 
     // Set the background image for the logo.
-    $logo = $theme->setting_file_url('logo', 'logo');
+    $logo = $OUTPUT->get_logo_url(null, 100);
     $css = theme_more_set_logo($css, $logo);
 
     // Set custom CSS.