diff --git a/lib/xmet/skew_t.py b/lib/xmet/skew_t.py
index 3a9bcb1..70fec70 100644
--- a/lib/xmet/skew_t.py
+++ b/lib/xmet/skew_t.py
@@ -134,12 +134,12 @@ class SkewTGraph():
         cr.set_source_rgba(1.0, 0.2, 0, 0.2)
 
         for temp in range(-140, 140, 10):
-            self.draw_adiabat(cr, x, y, temp, PRESSURE_MAX, lambda t, p: LAPSE_RATE_DRY)
+            self.draw_adiabat(cr, x, y, temp, 1000.0, lambda t, p: LAPSE_RATE_DRY)
 
         cr.set_source_rgba(0.3, 0.1, 0, 0.2)
 
         for temp in range(-140, 140, 10):
-            self.draw_adiabat(cr, x, y, temp, PRESSURE_MAX, moist_lapse_rate)
+            self.draw_adiabat(cr, x, y, temp, 1000.0, moist_lapse_rate)
 
         cr.restore()