diff --git a/src/libstrongswan/utils/utils/strerror.h b/src/libstrongswan/utils/utils/strerror.h
index e1b063842..f59649c2a 100644
--- a/src/libstrongswan/utils/utils/strerror.h
+++ b/src/libstrongswan/utils/utils/strerror.h
@@ -14,7 +14,8 @@
  */
 
 /**
- * @{ @ingroup utils
+ * @defgroup strerror_i strerror
+ * @{ @ingroup utils_i
  */
 
 #ifndef STRERROR_H_