diff --git a/src/usb_i2c.cpp b/src/usb_i2c.cpp
index 8eef91aa1cbeb70777e1b603a9de2afd8b0ec193..409161b59e5e8fda6af2436c5ec0dcc43ebd840e 100644
--- a/src/usb_i2c.cpp
+++ b/src/usb_i2c.cpp
@@ -61,6 +61,11 @@ void CUSBI2C::open(const std::string &serial)
       throw CUSBI2CException(_HERE_,"No FTDI device available with the desired serial number.");
     }
   }
+  else
+  {
+    /* handle exceptions */
+    throw CUSBI2CException(_HERE_,"No FTDI devices available.");
+  }
 }
 
 unsigned char CUSBI2C::get_revision(void)