diff --git a/lib/galaxy/tools/parameters/basic.py b/lib/galaxy/tools/parameters/basic.py
index acba4fbafe0..b10b51bdb5e 100644
--- a/lib/galaxy/tools/parameters/basic.py
+++ b/lib/galaxy/tools/parameters/basic.py
@@ -563,7 +563,7 @@ class SelectToolParameter( ToolParameter ):
         # FIXME: Currently only translating values back to labels if they
         #        are not dynamic
         if self.is_dynamic:
-            rval = value
+            rval = map( str, value )
         else:
             options = list( self.static_options )
             rval = []