diff --git a/src/diagnostics.lua b/src/diagnostics.lua
index 3b11798..02e5517 100644
--- a/src/diagnostics.lua
+++ b/src/diagnostics.lua
@@ -118,11 +118,16 @@ function M.validate_diagnostics(content, workspace_types, root_dir)
         local type_part = nil
         local brace_depth = 0
         local comment_depth = 0
-        local last_colon = nil
+        local line_comment = false
+        local type_colon = nil
         for i = 1, #line do
           local c = line:sub(i, i)
           local next_c = line:sub(i+1, i+1)
-          if c == "(" and next_c == "*" then
+          if c == "/" and next_c == "/" then
+            line_comment = true
+          elseif line_comment then
+            -- Skip everything after //
+          elseif c == "(" and next_c == "*" then
             comment_depth = comment_depth + 1
           elseif c == "*" and next_c == ")" and comment_depth > 0 then
             comment_depth = comment_depth - 1
@@ -130,15 +135,17 @@ function M.validate_diagnostics(content, workspace_types, root_dir)
             brace_depth = brace_depth + 1
           elseif c == "}" and comment_depth == 0 then
             brace_depth = brace_depth - 1
-          elseif c == ":" and brace_depth == 0 and comment_depth == 0 then
-            last_colon = i
+          elseif c == ":" and brace_depth == 0 and comment_depth == 0 and next_c ~= "=" then
+            -- Only capture colon that's NOT followed by = (not := assignment)
+            type_colon = i
           end
         end
-        if last_colon then
-          type_part = line:sub(last_colon + 1)
+        if type_colon then
+          type_part = line:sub(type_colon + 1)
         end
         if type_part then
           type_part = type_part:gsub("%s*%(%*.-%*%)", "")  -- Remove block comments (* ... *) with leading whitespace
+          type_part = type_part:gsub("%s*//.*$", "")      -- Remove line comments // ...
           type_part = type_part:gsub("%s*:=.*$", "")
           type_part = type_part:gsub("%s*;.*$", "")  -- Remove trailing semicolon
           type_part = type_part:gsub("%s*$", "")