diff --git a/src/process-monitor.c b/src/process-monitor.c
index e21ee1c..735879f 100644
--- a/src/process-monitor.c
+++ b/src/process-monitor.c
@@ -134,8 +134,7 @@ xtm_process_monitor_graph_surface_create (XtmProcessMonitor *monitor, gint width
 {
 	cairo_t *cr;
 	cairo_surface_t *graph_surface;
-	gfloat *peak;
-	gdouble step_size;
+	gdouble peak, step_size;
 	gint i;
 
 	if (monitor->history->len <= 1)
@@ -157,9 +156,9 @@ xtm_process_monitor_graph_surface_create (XtmProcessMonitor *monitor, gint width
 	cairo_move_to (cr, width, height);
 	for (i = 0; (step_size * (i - 1)) <= width; i++)
 	{
-		peak = &g_array_index (monitor->history, gfloat, i);
+		peak = g_array_index (monitor->history, gfloat, i);
 		cairo_translate (cr, -step_size, 0);
-		cairo_line_to (cr, width, (1.0 - ((gdouble)(*peak))) * height);
+		cairo_line_to (cr, width, (1.0 - peak) * height);
 	}
 
 	if (monitor->type == 0)
@@ -182,9 +181,9 @@ xtm_process_monitor_graph_surface_create (XtmProcessMonitor *monitor, gint width
 		cairo_move_to (cr, width, height);
 		for (i = 0; (step_size * (i - 1)) <= width; i++)
 		{
-			peak = &g_array_index (monitor->history_swap, gfloat, i);
+			peak = g_array_index (monitor->history_swap, gfloat, i);
 			cairo_translate (cr, -step_size, 0);
-			cairo_line_to (cr, width, (1.0 - ((gdouble)(*peak))) * height);
+			cairo_line_to (cr, width, (1.0 - peak) * height);
 		}
 		cairo_set_source_rgba (cr, 0.33, 0.04, 0.16, 0.3);
 		cairo_line_to (cr, width, height);