diff --git a/libcorpus2/CMakeLists.txt b/libcorpus2/CMakeLists.txt
index 9d0700052bd15aeca89a6ea792c221b0ed070424..e705ffff817643829c3f583d7f371c1dbfe1cd7c 100644
--- a/libcorpus2/CMakeLists.txt
+++ b/libcorpus2/CMakeLists.txt
@@ -3,7 +3,7 @@ PROJECT(corpus2)
 
 set(corpus2_ver_major "1")
 set(corpus2_ver_minor "0")
-set(corpus2_ver_patch "10")
+set(corpus2_ver_patch "11")
 
 
 if(NOT LIBCORPUS2_SRC_DATA_DIR)
diff --git a/libcorpus2/tag.h b/libcorpus2/tag.h
index 2713071f62976507a6d54b006ac440e776ec200a..9041ca445f03c4506123b8f38af41df289fbc794 100644
--- a/libcorpus2/tag.h
+++ b/libcorpus2/tag.h
@@ -34,6 +34,8 @@ typedef boost::int8_t idx_t;
 typedef PwrNlp::bitset<64> mask_t;
 BOOST_STRONG_TYPEDEF(boost::uint32_t, tagset_idx_t);
 
+const mask_t filled_mask(PwrNlp::filled_bitset<64>());
+
 /**
  * This is an extended version of a POS tag, which also includes a number
  * of attributes which may have values set.
diff --git a/libpwrutils/bitset.h b/libpwrutils/bitset.h
index a28a75729a318961a0eaaec238b46d5095c5a901..358b71ee112f8237899eb058187b9bf9af632cb3 100644
--- a/libpwrutils/bitset.h
+++ b/libpwrutils/bitset.h
@@ -37,6 +37,13 @@ static const size_t ulong_bits = sizeof(unsigned long) * CHAR_BIT;
 
 typedef bitset<ulong_bits> word_bitset;
 
+template<size_t S>
+std::bitset<S> filled_bitset()
+{
+	std::bitset<S> b = std::bitset<S>();
+	b.flip();
+	return b;
+}
 
 /**
  * Count set bits in a integral type.