diff --git a/libguile/ChangeLog b/libguile/ChangeLog
index a8566b530..a7b81f2c2 100644
--- a/libguile/ChangeLog
+++ b/libguile/ChangeLog
@@ -1,3 +1,9 @@
+2002-07-13  Neil Jerram  <neil@ossau.uklinux.net>
+
+	* eval.c (unmemocopy): Fix for
+	1001-local-eval-error-backtrace-segfaults (unmemoization crash
+	with internal definitions and local-eval).
+
 2002-07-12  Gary Houston  <ghouston@arglist.com>
 
 	* dynl.c: Don't define stub procedures if DYNAMIC_LINKING is not
diff --git a/libguile/eval.c b/libguile/eval.c
index 172cc2e4d..68e0b78e6 100644
--- a/libguile/eval.c
+++ b/libguile/eval.c
@@ -1472,7 +1472,9 @@ unmemocopy (SCM x, SCM env)
 	z = scm_cons (n, SCM_UNSPECIFIED);
 	ls = scm_cons (scm_sym_define, z);
 	if (!SCM_NULLP (env))
-	  SCM_SETCAR (SCM_CAR (env), scm_cons (n, SCM_CAAR (env)));
+	  env = scm_cons (scm_cons (scm_cons (n, SCM_CAAR (env)),
+				    SCM_CDAR (env)),
+			  SCM_CDR (env));
 	break;
       }
     case SCM_BIT8(SCM_MAKISYM (0)):