diff --git a/module/mes/scm.mes b/module/mes/scm.mes
index 805b0318..32fc13f6 100644
--- a/module/mes/scm.mes
+++ b/module/mes/scm.mes
@@ -126,11 +126,6 @@
 
 (define memv memq)
 
-(define (member x lst)
-  (if (null? lst) #f
-      (if (equal? x (car lst)) lst
-          (member x (cdr lst)))))
-
 
 ;;; Lists
 (define (make-list n . x)
diff --git a/src/lib.c b/src/lib.c
index 8b46898e..9fb74900 100644
--- a/src/lib.c
+++ b/src/lib.c
@@ -312,3 +312,21 @@ equal2_p (SCM a, SCM b)
     }
   return eq_p (a, b);
 }
+
+SCM
+member (SCM x, SCM a)
+{
+  switch (TYPE (x))
+    {
+    case TCHAR:
+    case TNUMBER:
+    case TKEYWORD:
+    case TSYMBOL:
+    case TSPECIAL:
+      return memq (x, a);
+    default:
+      while (a != cell_nil && equal2_p (x, CAR (a)) != cell_t)
+        a = CDR (a);
+    }
+  return a != cell_nil ? a : cell_f;
+}