diff --git a/Changes b/Changes
index ad8d4676..5ce6c7d8 100644
--- a/Changes
+++ b/Changes
@@ -17,6 +17,12 @@
   - Removed Data::Types as a test dependency as it was barely used
     and not necessary
 
+  [Bug fixes]
+
+  - PERL-489 references to scalars with both number and string slots internally
+    would crash on BSON encoding, rather than encode the string part as a
+    binary.
+
 v0.999.998.1 2014-11-12 15:10:40-05:00 America/New_York (TRIAL RELEASE)
 
   [!!! Incompatible Changes !!!]
diff --git a/perl_mongo.c b/perl_mongo.c
index da0f00b9..0007024f 100644
--- a/perl_mongo.c
+++ b/perl_mongo.c
@@ -1393,7 +1393,8 @@ append_sv (bson_t * bson, const char * in_key, SV *sv, stackette *stack, int is_
         croak ("type (%s) unhandled", HvNAME(SvSTASH(SvRV(sv))));
       }
     } else {
-      switch (SvTYPE (SvRV (sv))) {
+      SV *deref = SvRV(sv);
+      switch (SvTYPE (deref)) {
       case SVt_PVHV: {
         /* hash */
         bson_t child;
@@ -1411,14 +1412,16 @@ append_sv (bson_t * bson, const char * in_key, SV *sv, stackette *stack, int is_
         bson_append_array_end(bson, &child);
         break;
       }
-      case SVt_PV:
-        /* binary */
-
-        serialize_binary(bson, key, BSON_SUBTYPE_BINARY, SvRV(sv));
-        break;
-      default:
-        sv_dump(SvRV(sv));
-        croak ("type (ref) unhandled");
+      default: {
+          if ( SvPOK(deref) ) {
+            /* binary */
+            serialize_binary(bson, key, BSON_SUBTYPE_BINARY, deref);
+          }
+          else {
+            sv_dump(deref);
+            croak ("type (ref) unhandled");
+          }
+        }
       }
     }
   } else {
diff --git a/t/bson.t b/t/bson.t
index 9ae819d1..a3114d02 100644
--- a/t/bson.t
+++ b/t/bson.t
@@ -404,4 +404,15 @@ subtest "Checking hash key unicode support" => sub {
     is ( $obj->{$testkey}, 1 );
 };
 
+subtest "PERL-489 ref to PVNV" => sub {
+    my $value = 42.2;
+    $value = "hello";
+    is(
+        exception { $c->insert( { value => \$value } ) },
+        undef,
+        "inserting ref to PVNV is not fatal",
+    );
+};
+
+
 done_testing;