diff --git a/rc/base/haskell.kak b/rc/base/haskell.kak
index 341602e2..666dc344 100644
--- a/rc/base/haskell.kak
+++ b/rc/base/haskell.kak
@@ -57,7 +57,7 @@ def -hidden haskell-indent-on-new-line %{
 hook -group haskell-highlight global WinSetOption filetype=haskell %{ add-highlighter ref haskell }
 
 hook global WinSetOption filetype=haskell %{
-    set buffer completion_extra_word_char "'"
+    set window extra_word_chars "'"
     hook window InsertEnd  .* -group haskell-hooks  haskell-filter-around-selections
     hook window InsertChar \n -group haskell-indent haskell-indent-on-new-line
 }
diff --git a/rc/core/kakrc.kak b/rc/core/kakrc.kak
index 43494d5a..48503993 100644
--- a/rc/core/kakrc.kak
+++ b/rc/core/kakrc.kak
@@ -38,7 +38,7 @@ add-highlighter -group / regions -default code kakrc \
     # Add the language's grammar to the static completion list
     printf %s\\n "hook global WinSetOption filetype=kak %{
         set window static_words '${keywords}:${attributes}:${types}:${values}'
-        set -- window completion_extra_word_char '-'
+        set -- window extra_word_chars '-'
     }" | sed 's,|,:,g'
 
     # Highlight keywords. Teach \b that - does not create a word boundary
diff --git a/src/insert_completer.cc b/src/insert_completer.cc
index dd259756..087dd00a 100644
--- a/src/insert_completer.cc
+++ b/src/insert_completer.cc
@@ -79,8 +79,8 @@ WordDB& get_word_db(const Buffer& buffer)
 template<bool other_buffers>
 InsertCompletion complete_word(const SelectionList& sels, const OptionManager& options)
 {
-    auto& extra_word_char = options["completion_extra_word_char"].get<Vector<Codepoint, MemoryDomain::Options>>();
-    auto is_word_pred = [extra_word_char](Codepoint c) { return is_word(c) or contains(extra_word_char, c); };
+    ConstArrayView<Codepoint> extra_word_chars = options["extra_word_chars"].get<Vector<Codepoint, MemoryDomain::Options>>();
+    auto is_word_pred = [extra_word_chars](Codepoint c) { return is_word(c, extra_word_chars); };
 
     const Buffer& buffer = sels.buffer();
     BufferCoord cursor_pos = sels.main().cursor();
diff --git a/src/main.cc b/src/main.cc
index 85d79ea7..b5b5cddc 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -48,7 +48,9 @@ static const char* startup_info =
 " * `*` will now strip surrounding whitespaces from the selection\n"
 " * lint/grep/make next/prev commands have been renamed to more\n"
 "   explicit names (lint-next-error, grep-previous-match, ...)\n"
-" * ctags commands have been renamed to use the ctags- prefix\n";
+" * ctags commands have been renamed to use the ctags- prefix\n"
+" * completion_extra_word_char option is now extra_word_chars (note the plural form)\n"
+"   and is used for word selection commands\n";
 
 struct startup_error : runtime_error
 {
@@ -251,7 +253,7 @@ static void check_timeout(const int& timeout)
         throw runtime_error{"the minimum acceptable timeout is 50 milliseconds"};
 }
 
-static void check_extra_word_char(const Vector<Codepoint, MemoryDomain::Options>& extra_chars)
+static void check_extra_word_chars(const Vector<Codepoint, MemoryDomain::Options>& extra_chars)
 {
     if (contains_that(extra_chars, is_blank))
         throw runtime_error{"blanks are not accepted for extra completion characters"};
@@ -324,8 +326,8 @@ void register_options()
 
     reg.declare_option("debug", "various debug flags", DebugFlags::None);
     reg.declare_option("readonly", "prevent buffers from being modified", false);
-    reg.declare_option<Vector<Codepoint, MemoryDomain::Options>, check_extra_word_char>(
-        "completion_extra_word_char",
+    reg.declare_option<Vector<Codepoint, MemoryDomain::Options>, check_extra_word_chars>(
+        "extra_word_chars",
         "Additional characters to be considered as words for insert completion",
         {});
 }
diff --git a/src/selectors.cc b/src/selectors.cc
index 62ef8363..597619f8 100644
--- a/src/selectors.cc
+++ b/src/selectors.cc
@@ -36,17 +36,24 @@ Selection utf8_range(const Utf8Iterator& first, const Utf8Iterator& last)
     return {first.base().coord(), last.base().coord()};
 }
 
+ConstArrayView<Codepoint> get_extra_word_chars(const Context& context)
+{
+    return context.options()["extra_word_chars"].get<Vector<Codepoint, MemoryDomain::Options>>();
+}
+
 }
 
 template<WordType word_type>
 Optional<Selection>
 select_to_next_word(const Context& context, const Selection& selection)
 {
+    auto extra_word_chars = get_extra_word_chars(context);
     auto& buffer = context.buffer();
     Utf8Iterator begin{buffer.iterator_at(selection.cursor()), buffer};
     if (begin+1 == buffer.end())
         return {};
-    if (categorize<word_type>(*begin) != categorize<word_type>(*(begin+1)))
+    if (categorize<word_type>(*begin, extra_word_chars) !=
+        categorize<word_type>(*(begin+1), extra_word_chars))
         ++begin;
 
     if (not skip_while(begin, buffer.end(),
@@ -54,10 +61,12 @@ select_to_next_word(const Context& context, const Selection& selection)
         return {};
     Utf8Iterator end = begin+1;
 
-    if (word_type == Word and is_punctuation(*begin))
+    auto is_word = [&](Codepoint c) { return Kakoune::is_word<word_type>(c, extra_word_chars); };
+
+    if (is_word(*begin))
+        skip_while(end, buffer.end(), is_word);
+    else if (is_punctuation(*begin))
         skip_while(end, buffer.end(), is_punctuation);
-    else if (is_word<word_type>(*begin))
-        skip_while(end, buffer.end(), is_word<word_type>);
 
     skip_while(end, buffer.end(), is_horizontal_blank);
 
@@ -70,11 +79,13 @@ template<WordType word_type>
 Optional<Selection>
 select_to_next_word_end(const Context& context, const Selection& selection)
 {
+    auto extra_word_chars = get_extra_word_chars(context);
     auto& buffer = context.buffer();
     Utf8Iterator begin{buffer.iterator_at(selection.cursor()), buffer};
     if (begin+1 == buffer.end())
         return {};
-    if (categorize<word_type>(*begin) != categorize<word_type>(*(begin+1)))
+    if (categorize<word_type>(*begin, extra_word_chars) !=
+        categorize<word_type>(*(begin+1), extra_word_chars))
         ++begin;
 
     if (not skip_while(begin, buffer.end(),
@@ -83,10 +94,12 @@ select_to_next_word_end(const Context& context, const Selection& selection)
     Utf8Iterator end = begin;
     skip_while(end, buffer.end(), is_horizontal_blank);
 
-    if (word_type == Word and is_punctuation(*end))
+    auto is_word = [&](Codepoint c) { return Kakoune::is_word<word_type>(c, extra_word_chars); };
+
+    if (is_word(*end))
+        skip_while(end, buffer.end(), is_word);
+    else if (is_punctuation(*end))
         skip_while(end, buffer.end(), is_punctuation);
-    else if (is_word<word_type>(*end))
-        skip_while(end, buffer.end(), is_word<word_type>);
 
     return utf8_range(begin, end-1);
 }
@@ -97,22 +110,25 @@ template<WordType word_type>
 Optional<Selection>
 select_to_previous_word(const Context& context, const Selection& selection)
 {
+    auto extra_word_chars = get_extra_word_chars(context);
     auto& buffer = context.buffer();
     Utf8Iterator begin{buffer.iterator_at(selection.cursor()), buffer};
     if (begin == buffer.begin())
         return {};
-    if (categorize<word_type>(*begin) != categorize<word_type>(*(begin-1)))
+    if (categorize<word_type>(*begin, extra_word_chars) !=
+        categorize<word_type>(*(begin-1), extra_word_chars))
         --begin;
 
     skip_while_reverse(begin, buffer.begin(), [](Codepoint c){ return is_eol(c); });
     Utf8Iterator end = begin;
 
-    bool with_end = skip_while_reverse(end, buffer.begin(), is_horizontal_blank);
-    if (word_type == Word and is_punctuation(*end))
-        with_end = skip_while_reverse(end, buffer.begin(), is_punctuation);
+    auto is_word = [&](Codepoint c) { return Kakoune::is_word<word_type>(c, extra_word_chars); };
 
-    else if (is_word<word_type>(*end))
-        with_end = skip_while_reverse(end, buffer.begin(), is_word<word_type>);
+    bool with_end = skip_while_reverse(end, buffer.begin(), is_horizontal_blank);
+    if (is_word(*end))
+        with_end = skip_while_reverse(end, buffer.begin(), is_word);
+    else if (is_punctuation(*end))
+        with_end = skip_while_reverse(end, buffer.begin(), is_punctuation);
 
     return utf8_range(begin, with_end ? end : end+1);
 }
@@ -124,21 +140,25 @@ Optional<Selection>
 select_word(const Context& context, const Selection& selection,
             int count, ObjectFlags flags)
 {
+    auto extra_word_chars = get_extra_word_chars(context);
     auto& buffer = context.buffer();
+
+    auto is_word = [&](Codepoint c) { return Kakoune::is_word<word_type>(c, extra_word_chars); };
+
     Utf8Iterator first{buffer.iterator_at(selection.cursor()), buffer};
-    if (not is_word<word_type>(*first))
+    if (not is_word(*first))
         return {};
 
     Utf8Iterator last = first;
     if (flags & ObjectFlags::ToBegin)
     {
-        skip_while_reverse(first, buffer.begin(), is_word<word_type>);
-        if (not is_word<word_type>(*first))
+        skip_while_reverse(first, buffer.begin(), is_word);
+        if (not is_word(*first))
             ++first;
     }
     if (flags & ObjectFlags::ToEnd)
     {
-        skip_while(last, buffer.end(), is_word<word_type>);
+        skip_while(last, buffer.end(), is_word);
         if (not (flags & ObjectFlags::Inner))
             skip_while(last, buffer.end(), is_horizontal_blank);
         --last;
diff --git a/src/string.cc b/src/string.cc
index 89b7c3fe..1ab56481 100644
--- a/src/string.cc
+++ b/src/string.cc
@@ -429,7 +429,7 @@ Vector<StringView> wrap_lines(StringView text, ColumnCount max_width)
     Vector<StringView> lines;
     while (it != end)
     {
-        const CharCategories cat = categorize(*it);
+        const CharCategories cat = categorize(*it, {});
         if (cat == CharCategories::EndOfLine)
         {
             lines.emplace_back(line_begin.base(), it.base());
@@ -438,7 +438,7 @@ Vector<StringView> wrap_lines(StringView text, ColumnCount max_width)
         }
 
         Utf8It word_end = it+1;
-        while (word_end != end and categorize(*word_end) == cat)
+        while (word_end != end and categorize(*word_end, {}) == cat)
             ++word_end;
 
         while (word_end > line_begin and
diff --git a/src/unicode.hh b/src/unicode.hh
index eade3510..ba340b3a 100644
--- a/src/unicode.hh
+++ b/src/unicode.hh
@@ -6,6 +6,8 @@
 #include <locale>
 
 #include "units.hh"
+#include "array_view.hh"
+#include "containers.hh"
 
 namespace Kakoune
 {
@@ -30,13 +32,13 @@ inline bool is_blank(Codepoint c) noexcept
 enum WordType { Word, WORD };
 
 template<WordType word_type = Word>
-inline bool is_word(Codepoint c) noexcept
+inline bool is_word(Codepoint c, ConstArrayView<Codepoint> extra_word_chars = {}) noexcept
 {
-    return c == '_' or iswalnum((wchar_t)c);
+    return c == '_' or iswalnum((wchar_t)c) or contains(extra_word_chars, c);
 }
 
 template<>
-inline bool is_word<WORD>(Codepoint c) noexcept
+inline bool is_word<WORD>(Codepoint c, ConstArrayView<Codepoint>) noexcept
 {
     return not is_blank(c);
 }
@@ -65,13 +67,13 @@ enum class CharCategories
 };
 
 template<WordType word_type = Word>
-inline CharCategories categorize(Codepoint c) noexcept
+inline CharCategories categorize(Codepoint c, ConstArrayView<Codepoint> extra_word_chars) noexcept
 {
     if (is_eol(c))
         return CharCategories::EndOfLine;
     if (is_horizontal_blank(c))
         return CharCategories::Blank;
-    if (word_type == WORD or is_word(c))
+    if (word_type == WORD or is_word(c, extra_word_chars))
         return CharCategories::Word;
     return CharCategories::Punctuation;
 }
diff --git a/src/word_db.cc b/src/word_db.cc
index a486b86b..8bcfa250 100644
--- a/src/word_db.cc
+++ b/src/word_db.cc
@@ -32,7 +32,7 @@ static WordList get_words(StringView content, ConstArrayView<Codepoint> extra_wo
 
 static ConstArrayView<Codepoint> get_extra_word_chars(const Buffer& buffer)
 {
-    return buffer.options()["completion_extra_word_char"].get<Vector<Codepoint, MemoryDomain::Options>>();
+    return buffer.options()["extra_word_chars"].get<Vector<Codepoint, MemoryDomain::Options>>();
 }
 
 void WordDB::add_words(StringView line)
@@ -147,7 +147,7 @@ void WordDB::update_db()
 
 void WordDB::on_option_changed(const Option& option)
 {
-    if (option.name() == "completion_extra_word_char")
+    if (option.name() == "extra_word_chars")
         rebuild_db();
 }
 
diff --git a/test/normal/extra-word-chars/cmd b/test/normal/extra-word-chars/cmd
new file mode 100644
index 00000000..d81d8778
--- /dev/null
+++ b/test/normal/extra-word-chars/cmd
@@ -0,0 +1 @@
+ww
diff --git a/test/normal/extra-word-chars/in b/test/normal/extra-word-chars/in
new file mode 100644
index 00000000..ae82db18
--- /dev/null
+++ b/test/normal/extra-word-chars/in
@@ -0,0 +1 @@
+a-word another'one
diff --git a/test/normal/extra-word-chars/rc b/test/normal/extra-word-chars/rc
new file mode 100644
index 00000000..feb52869
--- /dev/null
+++ b/test/normal/extra-word-chars/rc
@@ -0,0 +1 @@
+set buffer extra_word_chars "-:'"
diff --git a/test/normal/extra-word-chars/selections b/test/normal/extra-word-chars/selections
new file mode 100644
index 00000000..05122515
--- /dev/null
+++ b/test/normal/extra-word-chars/selections
@@ -0,0 +1 @@
+another'one