diff --git a/src/SConscript b/src/SConscript
index 74adf3c..0b66d6a 100644
--- a/src/SConscript
+++ b/src/SConscript
@@ -255,7 +255,8 @@
             hpp_code('}')
     if namespace is not None:
         cpp_code('namespace {} {{'.format(namespace))
-    cpp_code(symbol_len_declaration + ' = {};'.format(len(data)))
+    if hpp_code is not None:
+        cpp_code(symbol_len_declaration + ' = {};'.format(len(data)))
     cpp_code(symbol_declaration + ' = {')
     cpp_code.indent()
     step = 16