diff --git a/pack.c b/pack.c
index 037a4a98bb..8d249d875f 100644
--- a/pack.c
+++ b/pack.c
@@ -751,6 +751,7 @@ pack_pack(int argc, VALUE *argv, VALUE ary)
 	    StringValue(from);
 	    ptr = RSTRING_PTR(from);
 	    plen = RSTRING_LEN(from);
+	    OBJ_INFECT(res, from);
 
 	    if (len == 0 && type == 'm') {
 		encodes(res, ptr, plen, type, 0);
@@ -778,6 +779,7 @@ pack_pack(int argc, VALUE *argv, VALUE ary)
 
 	  case 'M':		/* quoted-printable encoded string */
 	    from = rb_obj_as_string(NEXTFROM);
+	    OBJ_INFECT(res, from);
 	    if (len <= 1)
 		len = 72;
 	    qpencode(res, from, len);
@@ -803,6 +805,7 @@ pack_pack(int argc, VALUE *argv, VALUE ary)
 		}
 		else {
 		    t = StringValuePtr(from);
+		    OBJ_INFECT(res, from);
 		    rb_obj_taint(from);
 		}
 		if (!associates) {
@@ -1186,6 +1189,7 @@ pack_unpack_internal(VALUE str, VALUE fmt, int mode)
 		    len = (send - s) * 8;
 		bits = 0;
 		bitstr = rb_usascii_str_new(0, len);
+		OBJ_INFECT(bitstr, str);
 		t = RSTRING_PTR(bitstr);
 		for (i=0; i<len; i++) {
 		    if (i & 7) bits >>= 1;
@@ -1207,6 +1211,7 @@ pack_unpack_internal(VALUE str, VALUE fmt, int mode)
 		    len = (send - s) * 8;
 		bits = 0;
 		bitstr = rb_usascii_str_new(0, len);
+		OBJ_INFECT(bitstr, str);
 		t = RSTRING_PTR(bitstr);
 		for (i=0; i<len; i++) {
 		    if (i & 7) bits <<= 1;
@@ -1228,6 +1233,7 @@ pack_unpack_internal(VALUE str, VALUE fmt, int mode)
 		    len = (send - s) * 2;
 		bits = 0;
 		bitstr = rb_usascii_str_new(0, len);
+		OBJ_INFECT(bitstr, str);
 		t = RSTRING_PTR(bitstr);
 		for (i=0; i<len; i++) {
 		    if (i & 1)
@@ -1251,6 +1257,7 @@ pack_unpack_internal(VALUE str, VALUE fmt, int mode)
 		    len = (send - s) * 2;
 		bits = 0;
 		bitstr = rb_usascii_str_new(0, len);
+		OBJ_INFECT(bitstr, str);
 		t = RSTRING_PTR(bitstr);
 		for (i=0; i<len; i++) {
 		    if (i & 1)
diff --git a/test/ruby/test_pack.rb b/test/ruby/test_pack.rb
index 9d24c1994d..95f8e35226 100644
--- a/test/ruby/test_pack.rb
+++ b/test/ruby/test_pack.rb
@@ -862,4 +862,20 @@ EXPECTED
     assert_equal "hogefuga", "aG9nZWZ1Z2E=".unpack1("m")
     assert_equal "01000001", "A".unpack1("B*")
   end
+
+  def test_pack_infection
+    tainted_array_string = ["123456"]
+    tainted_array_string.first.taint
+    ['a', 'A', 'Z', 'B', 'b', 'H', 'h', 'u', 'M', 'm', 'P', 'p'].each do |f|
+      assert_predicate(tainted_array_string.pack(f), :tainted?)
+    end
+  end
+
+  def test_unpack_infection
+    tainted_string = "123456"
+    tainted_string.taint
+    ['a', 'A', 'Z', 'B', 'b', 'H', 'h', 'u', 'M', 'm'].each do |f|
+      assert_predicate(tainted_string.unpack(f).first, :tainted?)
+    end
+  end
 end