diff --git a/antoine.py b/antoine.py
index 68068c4..6c39220 100644
--- a/antoine.py
+++ b/antoine.py
@@ -1,4 +1,5 @@
-def antoine( a, T):
+def antoine( a: float, T: float) -> float:
+    '''
     # Ps = antoine( a, T)
     #
     # Uses Antoine's equation to obtain the vapor pressure of a substance given
@@ -21,6 +22,6 @@ def antoine( a, T):
     # Code originally by: James C. Sutherland
     # Modified by: Tyler R. Josephson
     # Changed comment
-    
+    '''
     Ps = 10.0**( a[:,0] - a[:,1] / ( a[:,2] + T ) )
     return Ps