diff --git a/metpy/calc/basic.py b/metpy/calc/basic.py
index 976a159f21e..2c583c8753d 100644
--- a/metpy/calc/basic.py
+++ b/metpy/calc/basic.py
@@ -28,7 +28,7 @@
 # The following variables are constants for a standard atmosphere
 t0 = 288. * units.kelvin
 p0 = 1013.25 * units.hPa
-gamma = 0.0065 * units('K/m')
+gamma = 0.006500000000000001 * units('K/m')
 
 
 @exporter.export