diff --git a/NEWS b/NEWS
index a86170091..ae0ad720a 100644
--- a/NEWS
+++ b/NEWS
@@ -33,6 +33,12 @@ X86/MacOSX 10.10 and 10.11 and AMD64/MacOSX 10.10 and 10.11.
 
 * Memcheck:
 
+  - Default value for --keep-stacktraces has been changed to alloc-and-free.
+    This has a small cost in memory (one word per malloc-ed block) but
+    allows memcheck to e.g. give the 3 stacktraces of a dangling reference:
+    Where the block was allocated, where it was freed, and where it is
+    acccessed after free.
+
   - A new monitor command 'xb <addr> <len>' shows the validity bits of
     <len> bytes at <addr>.  The monitor command 'xb' is easier to use
     than get_vbits when you need to associate byte data value with
diff --git a/memcheck/docs/mc-manual.xml b/memcheck/docs/mc-manual.xml
index 4b70e64a1..1aa7eff3e 100644
--- a/memcheck/docs/mc-manual.xml
+++ b/memcheck/docs/mc-manual.xml
@@ -990,7 +990,7 @@ is <option>--errors-for-leak-kinds=definite,possible</option>
 
   <varlistentry id="opt.keep-stacktraces" xreflabel="--keep-stacktraces">
     <term>
-      <option><![CDATA[--keep-stacktraces=alloc|free|alloc-and-free|alloc-then-free|none [default: alloc-then-free] ]]></option>
+      <option><![CDATA[--keep-stacktraces=alloc|free|alloc-and-free|alloc-then-free|none [default: alloc-and-free] ]]></option>
     </term>
     <listitem>
       <para>Controls which stack trace(s) to keep for malloc'd and/or
diff --git a/memcheck/mc_main.c b/memcheck/mc_main.c
index 674a50d71..e3ed7139a 100644
--- a/memcheck/mc_main.c
+++ b/memcheck/mc_main.c
@@ -5708,7 +5708,7 @@ UInt          MC_(clo_leak_check_heuristics)  = 0;
 Bool          MC_(clo_workaround_gcc296_bugs) = False;
 Int           MC_(clo_malloc_fill)            = -1;
 Int           MC_(clo_free_fill)              = -1;
-KeepStacktraces MC_(clo_keep_stacktraces)     = KS_alloc_then_free;
+KeepStacktraces MC_(clo_keep_stacktraces)     = KS_alloc_and_free;
 Int           MC_(clo_mc_level)               = 2;
 Bool          MC_(clo_show_mismatched_frees)  = True;
 Bool          MC_(clo_expensive_definedness_check) = False;
@@ -5907,7 +5907,7 @@ static void mc_print_usage(void)
 "    --malloc-fill=<hexnumber>        fill malloc'd areas with given value\n"
 "    --free-fill=<hexnumber>          fill free'd areas with given value\n"
 "    --keep-stacktraces=alloc|free|alloc-and-free|alloc-then-free|none\n"
-"        stack trace(s) to keep for malloc'd/free'd areas       [alloc-then-free]\n"
+"        stack trace(s) to keep for malloc'd/free'd areas       [alloc-and-free]\n"
 "    --show-mismatched-frees=no|yes   show frees that don't match the allocator? [yes]\n"
 , plo_default
    );
diff --git a/memcheck/tests/big_blocks_freed_list.stderr.exp b/memcheck/tests/big_blocks_freed_list.stderr.exp
index 3c4c7286f..d0fd803a6 100644
--- a/memcheck/tests/big_blocks_freed_list.stderr.exp
+++ b/memcheck/tests/big_blocks_freed_list.stderr.exp
@@ -4,12 +4,18 @@ Invalid read of size 1
  Address 0x........ is 1,000 bytes inside a block of size 1,000,015 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (big_blocks_freed_list.c:21)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (big_blocks_freed_list.c:19)
 
 Invalid read of size 1
    at 0x........: main (big_blocks_freed_list.c:23)
  Address 0x........ is 1,000 bytes inside a block of size 900,000 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (big_blocks_freed_list.c:20)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (big_blocks_freed_list.c:18)
 
 Invalid read of size 1
    at 0x........: main (big_blocks_freed_list.c:33)
@@ -20,24 +26,36 @@ Invalid read of size 1
  Address 0x........ is 2,000 bytes inside a block of size 900,000 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (big_blocks_freed_list.c:20)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (big_blocks_freed_list.c:18)
 
 Invalid read of size 1
    at 0x........: main (big_blocks_freed_list.c:41)
  Address 0x........ is 10 bytes inside a block of size 10,000 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (big_blocks_freed_list.c:28)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (big_blocks_freed_list.c:27)
 
 Invalid read of size 1
    at 0x........: main (big_blocks_freed_list.c:46)
  Address 0x........ is 10 bytes inside a block of size 1,000,015 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (big_blocks_freed_list.c:40)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (big_blocks_freed_list.c:39)
 
 Invalid read of size 1
    at 0x........: main (big_blocks_freed_list.c:55)
  Address 0x........ is 10 bytes inside a block of size 10,000 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (big_blocks_freed_list.c:28)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (big_blocks_freed_list.c:27)
 
 
 HEAP SUMMARY:
diff --git a/memcheck/tests/cond_ld.vgtest b/memcheck/tests/cond_ld.vgtest
index acc0bfe04..5c83e2689 100644
--- a/memcheck/tests/cond_ld.vgtest
+++ b/memcheck/tests/cond_ld.vgtest
@@ -1,4 +1,4 @@
 prog: cond_ld_st
 args: loads
-vgopts: -q
+vgopts: -q --keep-stacktraces=alloc-then-free
 stderr_filter_args: cond_ld_st
diff --git a/memcheck/tests/cond_st.vgtest b/memcheck/tests/cond_st.vgtest
index 2ccf00c4a..fbb8181a7 100644
--- a/memcheck/tests/cond_st.vgtest
+++ b/memcheck/tests/cond_st.vgtest
@@ -1,4 +1,4 @@
 prog: cond_ld_st
 args: stores
-vgopts: -q
+vgopts: -q --keep-stacktraces=alloc-then-free
 stderr_filter_args: cond_ld_st
diff --git a/memcheck/tests/custom_alloc.vgtest b/memcheck/tests/custom_alloc.vgtest
index 9c7fa4106..047275632 100644
--- a/memcheck/tests/custom_alloc.vgtest
+++ b/memcheck/tests/custom_alloc.vgtest
@@ -1,2 +1,2 @@
 prog: custom_alloc
-vgopts: -q
+vgopts: -q --keep-stacktraces=alloc-then-free
diff --git a/memcheck/tests/doublefree.stderr.exp b/memcheck/tests/doublefree.stderr.exp
index 9ed5375c7..7560e3a77 100644
--- a/memcheck/tests/doublefree.stderr.exp
+++ b/memcheck/tests/doublefree.stderr.exp
@@ -4,4 +4,7 @@ Invalid free() / delete / delete[] / realloc()
  Address 0x........ is 0 bytes inside a block of size 177 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (doublefree.c:10)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (doublefree.c:8)
 
diff --git a/memcheck/tests/err_disable1.stderr.exp b/memcheck/tests/err_disable1.stderr.exp
index 8762bf1d4..02bf2599d 100644
--- a/memcheck/tests/err_disable1.stderr.exp
+++ b/memcheck/tests/err_disable1.stderr.exp
@@ -10,6 +10,9 @@ Invalid read of size 1
  Address 0x........ is 5 bytes inside a block of size 10 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (err_disable1.c:27)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (err_disable1.c:26)
 
 
 --------- disabled (expect 0) ---------
@@ -23,6 +26,9 @@ Invalid read of size 1
  Address 0x........ is 5 bytes inside a block of size 10 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (err_disable1.c:27)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (err_disable1.c:26)
 
 
 --------- MULTI-LEVEL TEST (expect 2) ---------
@@ -33,6 +39,9 @@ Invalid read of size 1
  Address 0x........ is 5 bytes inside a block of size 10 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (err_disable1.c:27)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (err_disable1.c:26)
 
 Invalid read of size 1
    at 0x........: err (err_disable1.c:21)
@@ -40,6 +49,9 @@ Invalid read of size 1
  Address 0x........ is 5 bytes inside a block of size 10 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (err_disable1.c:27)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (err_disable1.c:26)
 
 
 --------- MULTI-LEVEL TEST end ---------
diff --git a/memcheck/tests/err_disable2.stderr.exp b/memcheck/tests/err_disable2.stderr.exp
index 82cd04f44..7146da7a0 100644
--- a/memcheck/tests/err_disable2.stderr.exp
+++ b/memcheck/tests/err_disable2.stderr.exp
@@ -7,6 +7,9 @@ Invalid read of size 1
  Address 0x........ is 5 bytes inside a block of size 10 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (err_disable2.c:28)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (err_disable2.c:27)
 
 
 --------- disabled (expect 0) ---------
diff --git a/memcheck/tests/err_disable3.stderr.exp b/memcheck/tests/err_disable3.stderr.exp
index 0f1f8b770..2b6d74d6e 100644
--- a/memcheck/tests/err_disable3.stderr.exp
+++ b/memcheck/tests/err_disable3.stderr.exp
@@ -15,6 +15,9 @@ Invalid read of size 1
  Address 0x........ is 5 bytes inside a block of size 10 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (err_disable3.c:42)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (err_disable3.c:41)
 
 
 --------- c: end ---------
@@ -32,4 +35,7 @@ Invalid read of size 1
  Address 0x........ is 5 bytes inside a block of size 10 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (err_disable3.c:42)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (err_disable3.c:41)
 
diff --git a/memcheck/tests/err_disable4.stderr.exp b/memcheck/tests/err_disable4.stderr.exp
index cfacfd783..acc01ad82 100644
--- a/memcheck/tests/err_disable4.stderr.exp
+++ b/memcheck/tests/err_disable4.stderr.exp
@@ -1506,6 +1506,9 @@ Invalid read of size 1
  Address 0x........ is 5 bytes inside a block of size 10 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (err_disable4.c:81)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (err_disable4.c:80)
 
 
 -------- Got 498 errors (expected 498 ==> PASS) ------
diff --git a/memcheck/tests/err_disable_arange1.stderr.exp b/memcheck/tests/err_disable_arange1.stderr.exp
index cb6a2db62..35257d16c 100644
--- a/memcheck/tests/err_disable_arange1.stderr.exp
+++ b/memcheck/tests/err_disable_arange1.stderr.exp
@@ -6,6 +6,9 @@ Invalid write of size 4
  Address 0x........ is 492 bytes inside a block of size 4,000 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (err_disable_arange1.c:15)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (err_disable_arange1.c:14)
 
 
 Disabling address error reporting for the range.
@@ -24,6 +27,9 @@ Invalid write of size 4
  Address 0x........ is 3,156 bytes inside a block of size 4,000 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (err_disable_arange1.c:15)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (err_disable_arange1.c:14)
 
 
 Exiting.  Expect warnings of 2 remaining ranges.
diff --git a/memcheck/tests/fprw.vgtest b/memcheck/tests/fprw.vgtest
index 6dfbf0cb4..4179391b1 100644
--- a/memcheck/tests/fprw.vgtest
+++ b/memcheck/tests/fprw.vgtest
@@ -1,2 +1,2 @@
-vgopts: -q
+vgopts: -q --keep-stacktraces=alloc-then-free
 prog:   fprw
diff --git a/memcheck/tests/malloc1.stderr.exp b/memcheck/tests/malloc1.stderr.exp
index b440a8380..bbf804122 100644
--- a/memcheck/tests/malloc1.stderr.exp
+++ b/memcheck/tests/malloc1.stderr.exp
@@ -5,6 +5,10 @@ Invalid write of size 1
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: really (malloc1.c:19)
    by 0x........: main (malloc1.c:9)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: really (malloc1.c:16)
+   by 0x........: main (malloc1.c:9)
 
 Invalid write of size 1
    at 0x........: really (malloc1.c:23)
diff --git a/memcheck/tests/malloc2.stderr.exp b/memcheck/tests/malloc2.stderr.exp
index f1a075b65..36fb84823 100644
--- a/memcheck/tests/malloc2.stderr.exp
+++ b/memcheck/tests/malloc2.stderr.exp
@@ -3,6 +3,9 @@ Invalid write of size 1
  Address 0x........ is 0 bytes inside a block of size 772 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (malloc2.c:49)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (malloc2.c:41)
 
 Invalid free() / delete / delete[] / realloc()
    at 0x........: free (vg_replace_malloc.c:...)
@@ -10,4 +13,7 @@ Invalid free() / delete / delete[] / realloc()
  Address 0x........ is 0 bytes inside a block of size 772 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (malloc2.c:49)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (malloc2.c:41)
 
diff --git a/memcheck/tests/memalign_test.stderr.exp b/memcheck/tests/memalign_test.stderr.exp
index aa8d58833..e9dc1afe5 100644
--- a/memcheck/tests/memalign_test.stderr.exp
+++ b/memcheck/tests/memalign_test.stderr.exp
@@ -4,4 +4,8 @@ Invalid free() / delete / delete[] / realloc()
  Address 0x........ is 0 bytes inside a block of size 111,110 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (memalign_test.c:23)
+ Block was alloc'd at
+   at 0x........: memalign (vg_replace_malloc.c:...)
+   by 0x........: valloc (vg_replace_malloc.c:...)
+   by 0x........: main (memalign_test.c:16)
 
diff --git a/memcheck/tests/noisy_child.stderr.exp b/memcheck/tests/noisy_child.stderr.exp
index 2f583438b..675fc643d 100644
--- a/memcheck/tests/noisy_child.stderr.exp
+++ b/memcheck/tests/noisy_child.stderr.exp
@@ -4,6 +4,9 @@ Invalid write of size 1
  Address 0x........ is 5 bytes inside a block of size 10 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (noisy_child.c:24)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (noisy_child.c:23)
 
 Invalid write of size 1
    at 0x........: do_parent_badness (noisy_child.c:16)
@@ -11,6 +14,9 @@ Invalid write of size 1
  Address 0x........ is 0 bytes after a block of size 10 free'd
    at 0x........: free (vg_replace_malloc.c:...)
    by 0x........: main (noisy_child.c:24)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (noisy_child.c:23)
 
 
 HEAP SUMMARY:
diff --git a/memcheck/tests/partial_load_dflt.vgtest b/memcheck/tests/partial_load_dflt.vgtest
index b1c6b27c4..a95bb6289 100644
--- a/memcheck/tests/partial_load_dflt.vgtest
+++ b/memcheck/tests/partial_load_dflt.vgtest
@@ -1,3 +1,4 @@
 prog: partial_load
+vgopts: --keep-stacktraces=alloc-then-free
 stderr_filter: filter_allocs
 stderr_filter_args: partial_load.c
diff --git a/memcheck/tests/partial_load_ok.vgtest b/memcheck/tests/partial_load_ok.vgtest
index d4003a77d..0c9caa108 100644
--- a/memcheck/tests/partial_load_ok.vgtest
+++ b/memcheck/tests/partial_load_ok.vgtest
@@ -1,4 +1,4 @@
 prog: partial_load
-vgopts: --partial-loads-ok=yes
+vgopts: --partial-loads-ok=yes --keep-stacktraces=alloc-then-free
 stderr_filter: filter_allocs
 stderr_filter_args: partial_load.c
diff --git a/memcheck/tests/suppfree.stderr.exp b/memcheck/tests/suppfree.stderr.exp
index 62f5cccc7..0340e61c1 100644
--- a/memcheck/tests/suppfree.stderr.exp
+++ b/memcheck/tests/suppfree.stderr.exp
@@ -12,4 +12,7 @@ Invalid free() / delete / delete[] / realloc()
    by 0x........: bbb (suppfree.c:17)
    by 0x........: aaa (suppfree.c:22)
    by 0x........: main (suppfree.c:36)
+ Block was alloc'd at
+   at 0x........: malloc (vg_replace_malloc.c:...)
+   by 0x........: main (suppfree.c:32)
 
diff --git a/memcheck/tests/test-plo-no.vgtest b/memcheck/tests/test-plo-no.vgtest
index 247a13489..14d4be32e 100644
--- a/memcheck/tests/test-plo-no.vgtest
+++ b/memcheck/tests/test-plo-no.vgtest
@@ -1,2 +1,2 @@
 prog: test-plo
-vgopts: -q
+vgopts: -q --keep-stacktraces=alloc-then-free
diff --git a/memcheck/tests/test-plo-yes.vgtest b/memcheck/tests/test-plo-yes.vgtest
index ace614cec..b37aeb5d3 100644
--- a/memcheck/tests/test-plo-yes.vgtest
+++ b/memcheck/tests/test-plo-yes.vgtest
@@ -1,3 +1,3 @@
 prereq: ! ../../tests/arch_test ppc32 && ! ../../tests/arch_test ppc64 && ! ../../tests/arch_test s390x && ! ../../tests/mips_features mips-be
 prog: test-plo
-vgopts: -q --partial-loads-ok=yes
+vgopts: -q --partial-loads-ok=yes  --keep-stacktraces=alloc-then-free
diff --git a/memcheck/tests/xml1.vgtest b/memcheck/tests/xml1.vgtest
index 4d83a9faa..6585b18f4 100644
--- a/memcheck/tests/xml1.vgtest
+++ b/memcheck/tests/xml1.vgtest
@@ -1,3 +1,3 @@
 prog: xml1
-vgopts: --xml=yes --xml-fd=2 --log-file=/dev/null
+vgopts: --xml=yes --xml-fd=2 --log-file=/dev/null --keep-stacktraces=alloc-then-free
 stderr_filter: filter_xml