diff --git a/src/main.lua b/src/main.lua
index 2467e78..f689aa9 100644
--- a/src/main.lua
+++ b/src/main.lua
@@ -568,8 +568,14 @@ function handlers.textDocument_semanticTokensFull(params)
 	for line in doc.content:gmatch("([^\n]*)\n") do
 		table.insert(lines, line)
 	end
+	
+	local total_lines = #lines
 
 	local function add_token(line, startChar, length, tokenType)
+		-- Validate line number is within bounds
+		if line < 0 or line >= total_lines then
+			return
+		end
 		local deltaLine = line
 		local deltaStart = startChar
 		if #tokens >= 4 then
@@ -595,7 +601,8 @@ function handlers.textDocument_semanticTokensFull(params)
 
 		if doc.variables then
 			for var_name, info in pairs(doc.variables) do
-				if info.line == lineNum then
+				-- Validate variable line number is within bounds
+				if info.line and info.line >= 0 and info.line < total_lines and info.line == lineNum then
 					local startChar = line:find(var_name, 1, true)
 					if startChar then
 						add_token(lineNum, startChar - 1, #var_name, "variable")
@@ -673,11 +680,14 @@ function handlers.textDocument_inlayHint(params)
 		table.insert(lines, line)
 	end
 
+	local total_lines = #lines
+
 	for i, line in ipairs(lines) do
 		local lineNum = i - 1
 		if doc.variables then
 			for var_name, info in pairs(doc.variables) do
-				if info.line == lineNum and info.data_type and info.data_type ~= "unknown" then
+				-- Validate line number is within bounds
+				if info.line and info.line >= 0 and info.line < total_lines and info.line == lineNum and info.data_type and info.data_type ~= "unknown" then
 					local colonPos = line:find(":", 1, true)
 					if colonPos then
 						table.insert(hints, {