diff --git a/xExtension-ImageProxy/README.md b/xExtension-ImageProxy/README.md
index 748c590..f930f8d 100644
--- a/xExtension-ImageProxy/README.md
+++ b/xExtension-ImageProxy/README.md
@@ -12,7 +12,8 @@ To use it, upload this entire directory to the FreshRSS `./extensions` directory
 
 * `scheme_https` (default: `0`): whether to proxy HTTPS resources
 
-* `scheme_default` (default: `http`): which scheme to use for resources that do not include one (if set to `-`, those will not be proxied)
+* `scheme_default` (default: `auto`): which scheme to use for resources that do not include one; if set to `-`, those will not be proxied;
+  if set along `scheme_include`, the scheme included in the URL will either be `auto`-matically derived from your current connection or the one explicitly specified
 
 * `scheme_include` (default: `0`): whether to include the scheme - `http*://` - in the proxied URL
 
diff --git a/xExtension-ImageProxy/configure.phtml b/xExtension-ImageProxy/configure.phtml
index 2e054f0..fb66144 100644
--- a/xExtension-ImageProxy/configure.phtml
+++ b/xExtension-ImageProxy/configure.phtml
@@ -24,6 +24,7 @@
 			<select name="image_proxy_scheme_default" id="image_proxy_scheme_default">
 				<option value="<?php echo htmlentities(FreshRSS_Context::$user_conf->image_proxy_scheme_default); ?>" selected="selected"><?php echo htmlentities(FreshRSS_Context::$user_conf->image_proxy_scheme_default); ?></option>
 				<option value="-">-</option>
+				<option value="auto">auto</option>
 				<option value="http">http</option>
 				<option value="https">https</option>
 			</select>
diff --git a/xExtension-ImageProxy/extension.php b/xExtension-ImageProxy/extension.php
index 8d0e5fe..ce4c9af 100644
--- a/xExtension-ImageProxy/extension.php
+++ b/xExtension-ImageProxy/extension.php
@@ -5,7 +5,7 @@ class ImageProxyExtension extends Minz_Extension {
 	private const PROXY_URL = 'https://images.weserv.nl/?url=';
 	private const SCHEME_HTTP = '1';
 	private const SCHEME_HTTPS = '';
-	private const SCHEME_DEFAULT = 'http';
+	private const SCHEME_DEFAULT = 'auto';
 	private const SCHEME_INCLUDE = '';
 	private const URL_ENCODE = '1';
 
@@ -78,9 +78,18 @@ class ImageProxyExtension extends Minz_Extension {
 			}
 		}
 		else if (empty($scheme)) {
-			if (substr(FreshRSS_Context::$user_conf->image_proxy_scheme_default,0, 4) !== 'http') return $url;
-			if (FreshRSS_Context::$user_conf->image_proxy_scheme_include) {
-				$url = FreshRSS_Context::$user_conf->image_proxy_scheme_default . '://' . $url;
+			if (FreshRSS_Context::$user_conf->image_proxy_scheme_default === 'auto') {
+				if (FreshRSS_Context::$user_conf->image_proxy_scheme_include) {
+					$url = ((!empty($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS'])!== 'off') ? 'https:' : 'http:') . $url;
+				}
+			}
+			else if (substr(FreshRSS_Context::$user_conf->image_proxy_scheme_default, 0, 4) === 'http') {
+				if (FreshRSS_Context::$user_conf->image_proxy_scheme_include) {
+					$url = FreshRSS_Context::$user_conf->image_proxy_scheme_default . ':' . $url;
+				}
+			}
+			else {  // do not proxy unschemed ("//path/...") URLs
+				return $url;
 			}
 		}
 		else {  // unknown/unsupported (non-http) scheme