diff --git a/src/lexer.l b/src/lexer.l
index 0b52e2a..f67c656 100644
--- a/src/lexer.l
+++ b/src/lexer.l
@@ -13,7 +13,8 @@
 ^[ \t]*\r?\n            { /* Ignore lines containing whitespace only */ }
 ^[ \t]*#.*\n            { /* Ignore comment-only lines */ }
 
-^[ \t]+ {
+
+^[ \t]* {
     int col = indent_stack.calculateColumn(yytext, yyleng);
     auto action = indent_stack.updateIndentation(col);
 
@@ -21,6 +22,13 @@
     if (action == IndentAction::Dedent) return yy::parser::token::TOK_DEDENT;
 }
 
+^. {
+    // Line starts with non-whitespace (column 0)
+    auto action = indent_stack.updateIndentation(0);
+    yyless(0);  
+    if (action == IndentAction::Dedent) return yy::parser::token::TOK_DEDENT;
+}
+
 \n                      { return yy::parser::token::TOK_NEWLINE; }
 
 def                     { return yy::parser::token::TOK_KW_DEF; }
diff --git a/test/lexer/06.in b/test/lexer/06.in
index 3ae113c..4242a87 100644
--- a/test/lexer/06.in
+++ b/test/lexer/06.in
@@ -3,6 +3,6 @@ def calculate(a, b=10):
     if result > 100:
         print("Large result:", result)
     return result
-
-# This is a comment
+    
+# this is a comment
 x = calculate(5, 15)
diff --git a/test/lexer/06.out b/test/lexer/06.out
index a482919..d62e9e9 100644
--- a/test/lexer/06.out
+++ b/test/lexer/06.out
@@ -39,7 +39,6 @@ KW_RETURN
 IDENTIFIER result
 NEWLINE
 DEDENT
-NEWLINE
 IDENTIFIER x
 ASSIGN
 IDENTIFIER calculate
@@ -49,4 +48,4 @@ COMMA
 NUMBER 15
 R_PAREN
 NEWLINE
-EOF
+EOF
\ No newline at end of file
diff --git a/test/lexer/07.out b/test/lexer/07.out
index bb61e99..8dfccba 100644
--- a/test/lexer/07.out
+++ b/test/lexer/07.out
@@ -18,4 +18,4 @@ IDENTIFIER very_long_variable_name_123
 ASSIGN
 STRING "test"
 NEWLINE
-EOF
+EOF
\ No newline at end of file
diff --git a/test/lexer/08.out b/test/lexer/08.out
index 098abc4..fe81bd9 100644
--- a/test/lexer/08.out
+++ b/test/lexer/08.out
@@ -16,4 +16,4 @@ NEWLINE
 KW_NOT
 IDENTIFIER flag
 NEWLINE
-EOF
+EOF
\ No newline at end of file