diff --git a/libguile/vectors.c b/libguile/vectors.c
index 321b49993..f9b4fc2fd 100644
--- a/libguile/vectors.c
+++ b/libguile/vectors.c
@@ -533,7 +533,9 @@ SCM_DEFINE (scm_vector_move_left_x, "vector-move-left!", 5, 0, 0,
 
   i = scm_to_unsigned_integer (start1, 0, len1);
   e = scm_to_unsigned_integer (end1, i, len1);
-  j = scm_to_unsigned_integer (start2, 0, len2 - (i-e));
+  SCM_ASSERT_RANGE (SCM_ARG3, end1, (e-i) < len2);
+  j = scm_to_unsigned_integer (start2, 0, len2);
+  SCM_ASSERT_RANGE (SCM_ARG5, start2, j <= len2 - (e - i));
   
   i *= inc1;
   e *= inc1;
@@ -571,7 +573,11 @@ SCM_DEFINE (scm_vector_move_right_x, "vector-move-right!", 5, 0, 0,
 
   i = scm_to_unsigned_integer (start1, 0, len1);
   e = scm_to_unsigned_integer (end1, i, len1);
-  j = scm_to_unsigned_integer (start2, 0, len2 - (i-e));
+  SCM_ASSERT_RANGE (SCM_ARG3, end1, (e-i) < len2);
+  j = scm_to_unsigned_integer (start2, 0, len2);
+  SCM_ASSERT_RANGE (SCM_ARG5, start2, j <= len2 - (e - i));
+  
+  j += (e - i);
   
   i *= inc1;
   e *= inc1;
diff --git a/test-suite/tests/vectors.test b/test-suite/tests/vectors.test
index fe856251f..f4df7de19 100644
--- a/test-suite/tests/vectors.test
+++ b/test-suite/tests/vectors.test
@@ -1,6 +1,6 @@
 ;;;; vectors.test --- test suite for Guile's vector functions -*- scheme -*-
 ;;;;
-;;;; Copyright (C) 2003, 2006 Free Software Foundation, Inc.
+;;;; Copyright (C) 2003, 2006, 2010 Free Software Foundation, Inc.
 ;;;; 
 ;;;; This library is free software; you can redistribute it and/or
 ;;;; modify it under the terms of the GNU Lesser General Public
@@ -62,3 +62,82 @@
     (equal? #("ab\u0100" "ab\u0100" "ab\u0100") 
             (make-vector 3 "ab\u0100"))))
 
+(with-test-prefix "vector-move-left!"
+
+  (pass-if-exception "before start" exception:out-of-range
+    (let ((a (vector 1 2 3 4 5 6 7 8 9))
+          (b (vector 10 20 30 40 50 60 70 80 90)))
+      (vector-move-left! a 3 5 b -1)))
+
+  (pass-if "beginning"
+    (let ((a (vector 1 2 3 4 5 6 7 8 9))
+          (b (vector 10 20 30 40 50 60 70 80 90)))
+      (vector-move-left! a 3 5 b 0)
+      (equal? b #(4 5 30 40 50 60 70 80 90))))
+
+  (pass-if "middle"
+    (let ((a (vector 1 2 3 4 5 6 7 8 9))
+          (b (vector 10 20 30 40 50 60 70 80 90)))
+      (vector-move-left! a 3 5 b 2)
+      (equal? b #(10 20 4 5 50 60 70 80 90))))
+
+  (pass-if "overlap -"
+    (let ((a (vector 1 2 3 4 5 6 7 8 9)))
+      (vector-move-left! a 3 5 a 2)
+      (equal? a #(1 2 4 5 5 6 7 8 9))))
+
+  (pass-if "overlap +"
+    (let ((a (vector 1 2 3 4 5 6 7 8 9)))
+      (vector-move-left! a 3 5 a 4)
+      (equal? a #(1 2 3 4 4 4 7 8 9))))
+
+  (pass-if "end"
+    (let ((a (vector 1 2 3 4 5 6 7 8 9))
+          (b (vector 10 20 30 40 50 60 70 80 90)))
+       (vector-move-left! a 3 5 b 7)
+       (equal? b #(10 20 30 40 50 60 70 4 5))))
+
+  (pass-if-exception "past end" exception:out-of-range
+    (let ((a (vector 1 2 3 4 5 6 7 8 9))
+          (b (vector 10 20 30 40 50 60 70 80 90)))
+      (vector-move-left! a 3 5 b 8))))
+
+(with-test-prefix "vector-move-right!"
+
+  (pass-if-exception "before start" exception:out-of-range
+    (let ((a (vector 1 2 3 4 5 6 7 8 9))
+          (b (vector 10 20 30 40 50 60 70 80 90)))
+      (vector-move-right! a 3 5 b -1)))
+
+  (pass-if "beginning"
+    (let ((a (vector 1 2 3 4 5 6 7 8 9))
+          (b (vector 10 20 30 40 50 60 70 80 90)))
+      (vector-move-right! a 3 5 b 0)
+      (equal? b #(4 5 30 40 50 60 70 80 90))))
+
+  (pass-if "middle"
+    (let ((a (vector 1 2 3 4 5 6 7 8 9))
+          (b (vector 10 20 30 40 50 60 70 80 90)))
+      (vector-move-right! a 3 5 b 2)
+      (equal? b #(10 20 4 5 50 60 70 80 90))))
+
+  (pass-if "overlap -"
+    (let ((a (vector 1 2 3 4 5 6 7 8 9)))
+      (vector-move-right! a 3 5 a 2)
+      (equal? a #(1 2 5 5 5 6 7 8 9))))
+
+  (pass-if "overlap +"
+    (let ((a (vector 1 2 3 4 5 6 7 8 9)))
+      (vector-move-right! a 3 5 a 4)
+      (equal? a #(1 2 3 4 4 5 7 8 9))))
+
+  (pass-if "end"
+    (let ((a (vector 1 2 3 4 5 6 7 8 9))
+          (b (vector 10 20 30 40 50 60 70 80 90)))
+       (vector-move-right! a 3 5 b 7)
+       (equal? b #(10 20 30 40 50 60 70 4 5))))
+
+  (pass-if-exception "past end" exception:out-of-range
+    (let ((a (vector 1 2 3 4 5 6 7 8 9))
+          (b (vector 10 20 30 40 50 60 70 80 90)))
+      (vector-move-right! a 3 5 b 8))))