1 files changed, 8 insertions, 6 deletions

diff --git a/type/GenericIO.class.php b/type/GenericIO.class.php
index 3a29948..b22b6d0 100644
--- a/type/GenericIO.class.php
+++ b/type/GenericIO.class.php
@@ -51,12 +51,14 @@ class Type_GenericIO extends Type_Base {
                         $i++;
                 }
 
-                $rrdgraph[] = sprintf('AREA:overlap#%s',
-                        $this->get_faded_color(
-                                $this->get_faded_color($this->colors[$sources[0]]),
-                                $this->get_faded_color($this->colors[$sources[1]])
-                        )
-                );
+                if (!$this->negative_io) {
+                        $rrdgraph[] = sprintf('AREA:overlap#%s',
+                                $this->get_faded_color(
+                                        $this->get_faded_color($this->colors[$sources[0]]),
+                                        $this->get_faded_color($this->colors[$sources[1]])
+                                )
+                        );
+                }
 
                 $i = 0;
                 foreach($sources as $source) {