diff --git a/calc.py b/calc.py
index 3916314..ab6a891 100755
--- a/calc.py
+++ b/calc.py
@@ -20,7 +20,7 @@ env = {
 	"range": range, "round": round, "min": min, "map": map,
 	"zip": zip, "xrange": xrange, "unicode": unicode,
 	"unichr": unichr, "type": type, "slice": slice, "ord": ord,
-	"chr": chr
+	"chr": chr, "str": str
 }
 
 libs = [