diff --git a/lib/galaxy/util/json.py b/lib/galaxy/util/json.py
index 319642b1436..b5ecb42501b 100644
--- a/lib/galaxy/util/json.py
+++ b/lib/galaxy/util/json.py
@@ -48,6 +48,8 @@ def swap_inf_nan( val ):
             return "__Infinity__"
         elif val == float("-inf"):
             return "__-Infinity__"
+        else:
+            return val
     else:
         return val