diff --git a/doc/developer/memtypes.rst b/doc/developer/memtypes.rst
index d43bc2555e..43cbe002cf 100644
--- a/doc/developer/memtypes.rst
+++ b/doc/developer/memtypes.rst
@@ -95,7 +95,7 @@ Usage
 
 .. c:function:: void *XCALLOC(struct memtype *mtype, size_t size)
 
-.. c:function:: void *XSTRDUP(struct memtype *mtype, size_t size)
+.. c:function:: void *XSTRDUP(struct memtype *mtype, const char *name)
 
    Allocation wrappers for malloc/calloc/realloc/strdup, taking an extra
    mtype parameter.