diff --git a/visma/io/tokenize.py b/visma/io/tokenize.py
index d0a0ac7..2293ba3 100644
--- a/visma/io/tokenize.py
+++ b/visma/io/tokenize.py
@@ -68,7 +68,7 @@ def getTerms(eqn):
     terms = []
     while x < len(eqn):
 
-        if ('a' <= eqn[x] <= 'z') or ('A' <= eqn[x] <= 'Z') or eqn[x] in greek:
+        if ('a' <= eqn[x] <= 'z') or ('A' <= eqn[x] <= 'Z') or eqn[x] in greek or eqn[x] in constants:
 
             buf = eqn[x]
             if x + 3 < len(eqn):
@@ -103,6 +103,10 @@ def getTerms(eqn):
                 terms.append("exp")
                 x += 1
                 continue
+            elif eqn[x] ==constants[0]:
+                terms.append(str(math.pi))
+                x += 1
+                continue
             elif eqn[x] == 'i':
                 terms.append("iota")
                 x += 1