diff --git a/core/config.class.php b/core/config.class.php
index c9b91651..62e22d7d 100644
--- a/core/config.class.php
+++ b/core/config.class.php
@@ -16,7 +16,7 @@ class Config {
 			'thumb_width' => 192, # index
 			'thumb_height' => 192, # index
 			'thumb_quality' => 75,  # index
-			'thumb_gd_mem_limit' => '8MB', # upload
+			'thumb_mem_limit' => '8MB', # upload
 			'tags_default' => 'map', # (ignored)
 			'tags_min' => '2', # tags
 			'upload_count' => 3, # upload
diff --git a/core/ext/image.ext.php b/core/ext/image.ext.php
index 98162f5e..d1e62cbe 100644
--- a/core/ext/image.ext.php
+++ b/core/ext/image.ext.php
@@ -45,7 +45,7 @@ class ImageIO extends Extension {
 			$sb->add_int_option("thumb_quality");
 			$sb->add_label(" % quality ");
 
-			$sb->add_shorthand_int_option("thumb_gd_mem_limit", "<br>Max GD memory use: ");
+			$sb->add_shorthand_int_option("thumb_mem_limit", "<br>Max memory use: ");
 
 			$event->panel->add_block($sb);
 		}
@@ -54,7 +54,7 @@ class ImageIO extends Extension {
 			$event->config->set_int_from_post("thumb_width");
 			$event->config->set_int_from_post("thumb_height");
 			$event->config->set_int_from_post("thumb_quality");
-			$event->config->set_int_from_post("thumb_gd_mem_limit");
+			$event->config->set_int_from_post("thumb_mem_limit");
 		}
 	}
 // }}}
@@ -99,8 +99,9 @@ class ImageIO extends Extension {
 		$w = $config->get_int("thumb_width");
 		$h = $config->get_int("thumb_height");
 		$q = $config->get_int("thumb_quality");
+		$mem = $config->get_int("thumb_max_memory") / 1024 / 1024; // IM takes memory in MB
 
-		exec("convert {$inname}[0] -geometry {$w}x{$h} -quality {$q} jpg:$outname");
+		exec("convert {$inname}[0] -limit memory {$mem} -geometry {$w}x{$h} -quality {$q} jpg:$outname");
 
 		return true;
 	}
diff --git a/ext/regen_thumb/main.php b/ext/regen_thumb/main.php
index 55f65fa2..adb17e9c 100644
--- a/ext/regen_thumb/main.php
+++ b/ext/regen_thumb/main.php
@@ -41,7 +41,8 @@ class RegenThumb extends Extension {
 		switch($program) {
 			case 'convert':
 				if(file_exists($f_thumb)) unlink($f_thumb);
-				exec("convert {$f_image}[0] -geometry {$w}x{$h} -quality {$q} jpg:$f_thumb");
+				$mem = $config->get_int("thumb_max_memory") / 1024 / 1024; // IM takes memory in MB
+				exec("convert {$f_image}[0] -limit memory {$mem} -geometry {$w}x{$h} -quality {$q} jpg:$f_thumb");
 				break;
 			case 'gd':
 				$this->make_thumb_gd($f_image, $f_thumb);