diff --git a/src/gmio_core/error.h b/src/gmio_core/error.h
index eba71b7..73c5002 100644
--- a/src/gmio_core/error.h
+++ b/src/gmio_core/error.h
@@ -44,6 +44,12 @@ enum gmio_error
      *  gmio_transfer::is_stop_requested_func() returned GMIO_TRUE */
     GMIO_ERROR_TRANSFER_STOPPED,
 
+    /*! An error occured after a call to a <stdio.h> function
+     *
+     *  The caller can check errno to get the real error number
+     */
+    GMIO_ERROR_STDIO,
+
     /*! Unknown error */
     GMIO_ERROR_UNKNOWN
 };
diff --git a/src/gmio_stl/stl_io.c b/src/gmio_stl/stl_io.c
index 1bdc609..c053822 100644
--- a/src/gmio_stl/stl_io.c
+++ b/src/gmio_stl/stl_io.c
@@ -46,7 +46,7 @@ int gmio_stl_read_file(
         gmio_buffer_deallocate(&trsf.buffer);
     }
     else {
-        error = GMIO_ERROR_UNKNOWN;
+        error = GMIO_ERROR_STDIO;
     }
 
     return error;
@@ -107,7 +107,7 @@ int gmio_stl_write_file(
         gmio_buffer_deallocate(&trsf.buffer);
     }
     else {
-        error = GMIO_ERROR_UNKNOWN;
+        error = GMIO_ERROR_STDIO;
     }
 
     return error;