diff --git a/module/mes/scm.mes b/module/mes/scm.mes
index 438568ad..805b0318 100644
--- a/module/mes/scm.mes
+++ b/module/mes/scm.mes
@@ -109,7 +109,7 @@
 (define assv-ref assq-ref)
 
 (define (assoc key alist)
-  (if (null? alist) #f ;; IF
+  (if (null? alist) #f
       (if (equal? key (caar alist)) (car alist)
           (assoc key (cdr alist)))))
 
@@ -124,14 +124,10 @@
         (let ((entry (set-cdr! entry value)))
           alist))))
 
-(define (memq x lst)
-  (if (null? lst) #f ;; IF
-      (if (eq? x (car lst)) lst
-          (memq x (cdr lst)))))
 (define memv memq)
 
 (define (member x lst)
-  (if (null? lst) #f ;; IF
+  (if (null? lst) #f
       (if (equal? x (car lst)) lst
           (member x (cdr lst)))))
 
diff --git a/src/lib.c b/src/lib.c
index 91497418..f660b8f6 100644
--- a/src/lib.c
+++ b/src/lib.c
@@ -243,3 +243,28 @@ xassq (SCM x, SCM a) ///for speed in core only
   while (a != cell_nil && x != CDAR (a)) a = CDR (a);
   return a != cell_nil ? CAR (a) : cell_f;
 }
+
+SCM
+memq (SCM x, SCM a)
+{
+  switch (TYPE (x))
+    {
+    case TCHAR:
+    case TNUMBER:
+      {
+        SCM v = VALUE (x);
+        while (a != cell_nil && v != VALUE (CAR (a))) a = CDR (a); break;
+      }
+    case TKEYWORD:
+      {
+        SCM v = STRING (x);
+        while (a != cell_nil && v != STRING (CAR (a))) a = CDR (a); break;
+      }
+      // case TSYMBOL:
+      // case TSPECIAL:
+    default:
+      while (a != cell_nil && x != CAR (a)) a = CDR (a); break;
+    }
+  return a != cell_nil ? a : cell_f;
+}
+