diff --git a/perl.h b/perl.h
index e31337a45130..0954a3984496 100644
--- a/perl.h
+++ b/perl.h
@@ -4107,6 +4107,9 @@ out there, Solaris being the most prominent.
 #endif
 #define UTF8fARG(u,l,p) (int)cBOOL(u), (UV)(l), (void*)(p)
 
+/* For printing a PADNAME. Ideally these would have been named
+ * PADNAMEf and PADNAMEfARG
+ */
 #define PNf UTF8f
 #define PNfARG(pn) (int)1, (UV)PadnameLEN(pn), (void *)PadnamePV(pn)
 
diff --git a/pod/perldiag.pod b/pod/perldiag.pod
index cdd940729678..838133ff5101 100644
--- a/pod/perldiag.pod
+++ b/pod/perldiag.pod
@@ -8328,6 +8328,15 @@ anonymous, using the C<sub {}> syntax.  When inner anonymous subs that
 reference variables in outer subroutines are created, they
 are automatically rebound to the current values of such variables.
 
+=item Variable "%s" will not stay shared after refalias
+
+(W closure) A refalias operation has been performed on a variable that is
+captured by one or more closures, and thus is shared between them.  As a
+result of the way it is currently implemented, the variable in the scope
+that performed has now become disconnected from those in other scopes, and
+now operates independently.  Updates to this variable will not be reflected
+in the others, or vice versa.
+
 =item vector argument not supported with alpha versions
 
 (S printf) The %vd (s)printf format does not support version objects
diff --git a/pp.c b/pp.c
index 5d3ecdfc45a6..8095336f8a51 100644
--- a/pp.c
+++ b/pp.c
@@ -7624,6 +7624,12 @@ PP(pp_refassign)
     case 0:
     {
         SV * const old = PAD_SV(ARGTARG);
+        if(SvREFCNT(old) > 1) {
+            PADNAME *pn = PadlistNAMESARRAY(CvPADLIST(find_runcv(NULL)))[ARGTARG];
+            warner(packWARN(WARN_CLOSURE),
+                "Variable \"%" PNf "\" will not stay shared after refalias",
+                PNfARG(pn));
+        }
         PAD_SETSV(ARGTARG, SvREFCNT_inc_NN(SvRV(sv)));
         SvREFCNT_dec(old);
         if ((PL_op->op_private & (OPpLVAL_INTRO|OPpPAD_STATE))
diff --git a/t/op/lvref.t b/t/op/lvref.t
index 1435aa9f5125..1c52dfe9acbe 100644
--- a/t/op/lvref.t
+++ b/t/op/lvref.t
@@ -5,7 +5,7 @@ BEGIN {
     set_up_inc("../lib");
 }
 
-plan 203;
+plan 204;
 
 eval '\$x = \$y';
 like $@, qr/^Experimental aliasing via reference not enabled/,
@@ -626,6 +626,9 @@ like $@,
 # Miscellaneous
 
 {
+  my $warnings = "";
+  local $SIG{__WARN__} = sub { $warnings .= $_[0]; };
+
   local $::TODO = ' ';
   my($x,$y);
   sub {
@@ -635,6 +638,10 @@ like $@,
     is \$x, \$y, 'lexical alias affects outer closure';
   }->();
   is \$x, \$y, 'lexical alias affects outer sub where vars are declared';
+
+  undef $::TODO;
+  like $warnings, qr/^Variable "\$x" will not stay shared after refalias /,
+    'warning emitted by refalias on closure shared variable';
 }
 
 { # PADSTALE has a double meaning