diff --git a/libraries/fc/src/exception.cpp b/libraries/fc/src/exception.cpp
index 14b4a3be800..b7a8cb0e1b8 100644
--- a/libraries/fc/src/exception.cpp
+++ b/libraries/fc/src/exception.cpp
@@ -219,6 +219,7 @@ namespace fc
       } catch( ... ) {
          ss << "<- exception in to_string.\n";
       }
+      return ss.str();
    }
 
    /**