diff --git a/src/clang_tu.cc b/src/clang_tu.cc
index d10ed746..22032742 100644
--- a/src/clang_tu.cc
+++ b/src/clang_tu.cc
@@ -43,7 +43,7 @@ static Pos Decomposed2LineAndCol(const SourceManager &SM,
         while (i < P.size() && (uint8_t)P[i] >= 128 && (uint8_t)P[i] < 192)
           i++;
   }
-  return {(int16_t)std::min<int>(l, INT16_MAX),
+  return {(uint16_t)std::min<int>(l, UINT16_MAX),
           (int16_t)std::min<int>(c, INT16_MAX)};
 }
 
diff --git a/src/indexer.cc b/src/indexer.cc
index b6653fc3..5b730fe6 100644
--- a/src/indexer.cc
+++ b/src/indexer.cc
@@ -1151,8 +1151,8 @@ public:
 };
 } // namespace
 
-const int IndexFile::kMajorVersion = 19;
-const int IndexFile::kMinorVersion = 1;
+const int IndexFile::kMajorVersion = 20;
+const int IndexFile::kMinorVersion = 0;
 
 IndexFile::IndexFile(const std::string &path, const std::string &contents)
     : path(path), file_contents(contents) {}
diff --git a/src/message_handler.cc b/src/message_handler.cc
index 7179931d..a770eb75 100644
--- a/src/message_handler.cc
+++ b/src/message_handler.cc
@@ -320,9 +320,9 @@ void EmitSemanticHighlight(DB *db, WorkingFile *wfile, QueryFile &file) {
       // but we still want to keep the range for jumping to definition.
       std::string_view concise_name =
           detailed_name.substr(0, detailed_name.find('<'));
-      int16_t start_line = sym.range.start.line;
+      uint16_t start_line = sym.range.start.line;
       int16_t start_col = sym.range.start.column;
-      if (start_line < 0 || start_line >= wfile->index_lines.size())
+      if (start_line >= wfile->index_lines.size())
         continue;
       std::string_view line = wfile->index_lines[start_line];
       sym.range.end.line = start_line;
diff --git a/src/messages/ccls_navigate.cc b/src/messages/ccls_navigate.cc
index f2a6ac44..cb85ba7c 100644
--- a/src/messages/ccls_navigate.cc
+++ b/src/messages/ccls_navigate.cc
@@ -38,7 +38,7 @@ void MessageHandler::ccls_navigate(JsonReader &reader, ReplyOnce &reply) {
     if (auto line =
             wf->GetIndexPosFromBufferPos(ls_pos.line, &ls_pos.character, false))
       ls_pos.line = *line;
-  Pos pos{(int16_t)ls_pos.line, (int16_t)ls_pos.character};
+  Pos pos{(uint16_t)ls_pos.line, (int16_t)ls_pos.character};
 
   Maybe<Range> res;
   switch (param.direction[0]) {
diff --git a/src/position.cc b/src/position.cc
index c615c2b9..c572421b 100644
--- a/src/position.cc
+++ b/src/position.cc
@@ -16,7 +16,7 @@
 namespace ccls {
 Pos Pos::FromString(const std::string &encoded) {
   char *p = const_cast<char *>(encoded.c_str());
-  int16_t line = int16_t(strtol(p, &p, 10)) - 1;
+  uint16_t line = uint16_t(strtoul(p, &p, 10) - 1);
   assert(*p == ':');
   p++;
   int16_t column = int16_t(strtol(p, &p, 10)) - 1;
@@ -32,14 +32,14 @@ std::string Pos::ToString() {
 Range Range::FromString(const std::string &encoded) {
   Pos start, end;
   char *p = const_cast<char *>(encoded.c_str());
-  start.line = int16_t(strtol(p, &p, 10)) - 1;
+  start.line = uint16_t(strtoul(p, &p, 10) - 1);
   assert(*p == ':');
   p++;
   start.column = int16_t(strtol(p, &p, 10)) - 1;
   assert(*p == '-');
   p++;
 
-  end.line = int16_t(strtol(p, &p, 10)) - 1;
+  end.line = uint16_t(strtoul(p, &p, 10) - 1);
   assert(*p == ':');
   p++;
   end.column = int16_t(strtol(p, nullptr, 10)) - 1;
@@ -49,7 +49,7 @@ Range Range::FromString(const std::string &encoded) {
 bool Range::Contains(int line, int column) const {
   if (line > INT16_MAX)
     return false;
-  Pos p{(int16_t)line, (int16_t)std::min<int>(column, INT16_MAX)};
+  Pos p{(uint16_t)line, (int16_t)std::min<int>(column, INT16_MAX)};
   return !(p < start) && p < end;
 }
 
diff --git a/src/position.hh b/src/position.hh
index 0a08452b..35b1df9e 100644
--- a/src/position.hh
+++ b/src/position.hh
@@ -10,12 +10,12 @@
 
 namespace ccls {
 struct Pos {
-  int16_t line = -1;
+  uint16_t line = 0;
   int16_t column = -1;
 
   static Pos FromString(const std::string &encoded);
 
-  bool Valid() const { return line >= 0; }
+  bool Valid() const { return column >= 0; }
   std::string ToString();
 
   // Compare two Positions and check if they are equal. Ignores the value of