diff --git a/src/commands.cc b/src/commands.cc
index 3dced933..34e14967 100644
--- a/src/commands.cc
+++ b/src/commands.cc
@@ -29,6 +29,7 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <malloc.h>
 
 namespace Kakoune
 {
@@ -832,6 +833,7 @@ const CommandDesc debug_cmd = {
             write_debug("BufferMeta: " + to_string(UsedMemory<MemoryDomain::BufferMeta>::byte_count));
             write_debug("WordDB: " + to_string(UsedMemory<MemoryDomain::WordDB>::byte_count));
             write_debug("Undefined: " + to_string(UsedMemory<MemoryDomain::Undefined>::byte_count));
+            write_debug("Malloced: " + to_string(mallinfo().uordblks));
         }
         else
             throw runtime_error("unknown debug command '" + parser[0] + "'");
diff --git a/src/interned_string.hh b/src/interned_string.hh
index 25c84a85..8357ba85 100644
--- a/src/interned_string.hh
+++ b/src/interned_string.hh
@@ -20,7 +20,7 @@ private:
     void acquire(size_t slot);
     void release(size_t slot) noexcept;
 
-    UnorderedMap<StringView, size_t> m_slot_map;
+    UnorderedMap<StringView, size_t, MemoryDomain::InternedString> m_slot_map;
     Vector<size_t, MemoryDomain::InternedString> m_free_slots;
     struct DataAndRefCount
     {
diff --git a/src/unit_tests.cc b/src/unit_tests.cc
index 845b9a3e..d4a78784 100644
--- a/src/unit_tests.cc
+++ b/src/unit_tests.cc
@@ -82,17 +82,17 @@ void test_word_db()
     WordDB word_db(buffer);
     auto res = word_db.find_matching("", prefix_match);
     std::sort(res.begin(), res.end());
-    kak_assert(res == std::vector<InternedString>{ "allo" COMMA "kanaky" COMMA "mutch" COMMA "tchaa" COMMA "tchou" });
+    kak_assert(res == WordDB::WordList{ "allo" COMMA "kanaky" COMMA "mutch" COMMA "tchaa" COMMA "tchou" });
     kak_assert(word_db.get_word_occurences("tchou") == 3);
     kak_assert(word_db.get_word_occurences("allo") == 1);
     buffer.erase(buffer.iterator_at({1, 6}), buffer.iterator_at({4, 0}));
     res = word_db.find_matching("", prefix_match);
     std::sort(res.begin(), res.end());
-    kak_assert(res == std::vector<InternedString>{ "allo" COMMA "mutch" COMMA "tchou" });
+    kak_assert(res == WordDB::WordList{ "allo" COMMA "mutch" COMMA "tchou" });
     buffer.insert(buffer.iterator_at({1, 0}), "re");
     res = word_db.find_matching("", subsequence_match);
     std::sort(res.begin(), res.end());
-    kak_assert(res == std::vector<InternedString>{ "allo" COMMA "mutch" COMMA "retchou" COMMA "tchou" });
+    kak_assert(res == WordDB::WordList{ "allo" COMMA "mutch" COMMA "retchou" COMMA "tchou" });
 }
 
 void test_utf8()
diff --git a/src/word_db.cc b/src/word_db.cc
index cf79afdc..a2dce1cf 100644
--- a/src/word_db.cc
+++ b/src/word_db.cc
@@ -28,7 +28,7 @@ UsedLetters used_letters(StringView str)
 
 static WordDB::WordList get_words(const InternedString& content)
 {
-    std::vector<InternedString> res;
+    WordDB::WordList res;
     using Iterator = utf8::iterator<const char*, utf8::InvalidPolicy::Pass>;
     const char* word_start = content.begin();
     bool in_word = false;
diff --git a/src/word_db.hh b/src/word_db.hh
index 50496113..e50e0edc 100644
--- a/src/word_db.hh
+++ b/src/word_db.hh
@@ -22,13 +22,13 @@ public:
     WordDB(const WordDB&) = delete;
     WordDB(WordDB&&) = default;
 
-    using WordList = std::vector<InternedString>;
+    using WordList = Vector<InternedString, MemoryDomain::WordDB>;
     template<typename MatchFunc>
     WordList find_matching(StringView str, MatchFunc match)
     {
         update_db();
         const UsedLetters letters = used_letters(str);
-        std::vector<InternedString> res;
+        WordList res;
         for (auto&& word : m_words)
         {
             if ((letters & word.second.letters) == letters and