diff --git a/files.moon b/files.moon
index 7f23490..bdf95e3 100644
--- a/files.moon
+++ b/files.moon
@@ -143,7 +143,11 @@ Files.get_line_number = (str, pos)->
 
 Files.get_line = (str, line_no)->
     line_starts = Files.get_line_starts(str)
-    return str\sub(line_starts[line_no] or 1, (line_starts[line_no+1] or 1) - 2)
+    start = line_starts[line_no]
+    return unless start
+    stop = line_starts[line_no+1]
+    return unless stop
+    return str\sub(start, stop - 2)
 
 get_lines = re.compile([[
     lines <- {| line (%nl line)* |}
diff --git a/parser.moon b/parser.moon
index 1ffa2d4..cf67205 100644
--- a/parser.moon
+++ b/parser.moon
@@ -46,17 +46,18 @@ NOMSU_DEFS = with {}
         err_pos = start_pos
         line_no = files.get_line_number(src, err_pos)
         --src = files.read(userdata.source.filename)
-        prev_line = line_no == 1 and "" or files.get_line(src, line_no-1)
+        prev_line = line_no == 1 and nil or files.get_line(src, line_no-1)
         err_line = files.get_line(src, line_no)
         next_line = files.get_line(src, line_no+1)
         i = err_pos-files.get_line_starts(src)[line_no]
         j = i + (end_pos-start_pos)
         pointer = ("-")\rep(i) .. "^"
         err_msg = colored.bright colored.yellow colored.onred (err_msg or "Parse error").." at #{userdata.source.filename}:#{line_no}:"
-        if #prev_line > 0 then err_msg ..= "\n"..colored.dim(prev_line)
-        err_line = colored.white(err_line\sub(1, i))..colored.bright(colored.red(err_line\sub(i+1,j+1)))..colored.dim(err_line\sub(j+2,-1))
-        err_msg ..= "\n#{err_line}\n#{colored.red pointer}"
-        if #next_line > 0 then err_msg ..= "\n"..colored.dim(next_line)
+        if prev_line then err_msg ..= "\n"..colored.dim(prev_line)
+        if err_line
+            err_line = colored.white(err_line\sub(1, i))..colored.bright(colored.red(err_line\sub(i+1,j+1)))..colored.dim(err_line\sub(j+2,-1))
+            err_msg ..= "\n#{err_line}\n#{colored.red pointer}"
+        if next_line then err_msg ..= "\n"..colored.dim(next_line)
         seen_errors[start_pos] = err_msg
         return true
 
@@ -110,10 +111,8 @@ Parser.parse = (nomsu_code, source=nil, version=nil)->
         errors: {}, :source, comments: {}
     }
     tree = Parser.patterns[syntax_version]\match(nomsu_code, nil, userdata)
-    unless tree
+    if not tree or type(tree) == 'number'
         error "In file #{colored.blue tostring(source or "<unknown>")} failed to parse:\n#{colored.onyellow colored.black nomsu_code}"
-    if type(tree) == 'number'
-        return nil
 
     if next(userdata.errors)
         keys = [k for k,v in pairs(userdata.errors)]