diff --git a/joy/parser.py b/joy/parser.py
index 6d3a379..de8a873 100644
--- a/joy/parser.py
+++ b/joy/parser.py
@@ -41,7 +41,7 @@ from .utils.stack import list_to_stack
 
 
 #TODO: explain the details of float lits and strings.
-FLOAT = r'-?\d+\.\d*(e(-|\+)\d+)+'
+FLOAT = r'-?\d+\.\d*(e(-|\+)\d+)?'
 INT = r'-?\d+'
 SYMBOL = r'[•\w!@$%^&*()_+<>?|\/;:`~,.=-]+'
 BRACKETS = r'\[|\]'