diff --git a/src/core/common/gfal_common_plugin_interface.h b/src/core/common/gfal_common_plugin_interface.h
index 24e7b9e..28598ea 100644
--- a/src/core/common/gfal_common_plugin_interface.h
+++ b/src/core/common/gfal_common_plugin_interface.h
@@ -45,7 +45,7 @@ extern "C"
/*
* Helper for the versioned plugin names
*/
-#define GFAL2_PLUGIN_VERSIONED(plugin, version) plugin"-"version
+#define GFAL2_PLUGIN_VERSIONED(plugin, version) plugin "-" version
/**
classical data access plugin