diff --git a/runtime/lua/vim/diagnostic.lua b/runtime/lua/vim/diagnostic.lua
index 0ffc263ec1..2a26a36d10 100644
--- a/runtime/lua/vim/diagnostic.lua
+++ b/runtime/lua/vim/diagnostic.lua
@@ -467,13 +467,14 @@ local function next_diagnostic(position, search_forward, bufnr, opts, namespace)
       lnum = (lnum + line_count) % line_count
     end
     if line_diagnostics[lnum] and not vim.tbl_isempty(line_diagnostics[lnum]) then
+      local line_length = #vim.api.nvim_buf_get_lines(bufnr,  lnum, lnum + 1, true)[1]
       local sort_diagnostics, is_next
       if search_forward then
         sort_diagnostics = function(a, b) return a.col < b.col end
-        is_next = function(diagnostic) return diagnostic.col > position[2] end
+        is_next = function(d) return math.min(d.col, line_length - 1) > position[2] end
       else
         sort_diagnostics = function(a, b) return a.col > b.col end
-        is_next = function(diagnostic) return diagnostic.col < position[2] end
+        is_next = function(d) return math.min(d.col, line_length - 1) < position[2] end
       end
       table.sort(line_diagnostics[lnum], sort_diagnostics)
       if i == 0 then
diff --git a/test/functional/lua/diagnostic_spec.lua b/test/functional/lua/diagnostic_spec.lua
index 00e261c01d..cdf9a8a834 100644
--- a/test/functional/lua/diagnostic_spec.lua
+++ b/test/functional/lua/diagnostic_spec.lua
@@ -686,6 +686,19 @@ describe('vim.diagnostic', function()
         return vim.diagnostic.get_prev_pos { namespace = diagnostic_ns }
       ]])
     end)
+
+    it('works with diagnostics past the end of the line #16349', function()
+      eq({4, 0}, exec_lua [[
+        vim.diagnostic.set(diagnostic_ns, diagnostic_bufnr, {
+          make_error('Diagnostic #1', 3, 9001, 3, 9001),
+          make_error('Diagnostic #2', 4, 0, 4, 0),
+        })
+        vim.api.nvim_win_set_buf(0, diagnostic_bufnr)
+        vim.api.nvim_win_set_cursor(0, {1, 1})
+        vim.diagnostic.goto_next { float = false }
+        return vim.diagnostic.get_next_pos { namespace = diagnostic_ns }
+      ]])
+    end)
   end)
 
   describe('get_prev_pos()', function()