diff --git a/src/interpreter.rs b/src/interpreter.rs
index 72ef37c..9e05216 100644
--- a/src/interpreter.rs
+++ b/src/interpreter.rs
@@ -526,6 +526,7 @@ impl Interpreter {
                 Operator::Multiply => Ok(Value::Int(left * right)),
                 Operator::Divide => Ok(Value::Int(left / right)),
                 Operator::Equals => Ok(Value::Bool(left == right)),
+                Operator::Modulo => Ok(Value::Int(left % right)),
             },
             _ => Err(Error::new_runtime(
                 "Binary operation on non-numeric values".to_string(),
diff --git a/src/lexer.rs b/src/lexer.rs
index f3bbc55..10f50f8 100644
--- a/src/lexer.rs
+++ b/src/lexer.rs
@@ -56,8 +56,12 @@ pub enum TokenKind {
     Minus,
     Asterisk,
     Slash,
+    Percent,
     PlusEquals,
     MinusEquals,
+    StarEquals,
+    SlashEquals,
+    PercentEquals,
     Colon,
     Dot,
     DblDot,
@@ -178,7 +182,14 @@ impl Lexer {
                     self.create_token(TokenKind::Minus)
                 }
             }
-            Some('*') => self.create_token(TokenKind::Asterisk),
+            Some('*') => {
+                if self.peek_char() == Some('=') {
+                    self.read_char();
+                    self.create_token(TokenKind::StarEquals)
+                } else {
+                    self.create_token(TokenKind::Asterisk)
+                }
+            }
             Some(':') => self.create_token(TokenKind::Colon),
             Some('/') => {
                 if self.peek_char() == Some('/') {
@@ -199,10 +210,21 @@ impl Lexer {
                         self.read_char();
                     }
                     return self.next_token();
+                } else if self.peek_char() == Some('=') {
+                    self.read_char();
+                    self.create_token(TokenKind::SlashEquals)
                 } else {
                     return self.create_token(TokenKind::Slash);
                 }
             }
+            Some('%') => {
+                if self.peek_char() == Some('=') {
+                    self.read_char();
+                    self.create_token(TokenKind::PercentEquals)
+                } else {
+                    self.create_token(TokenKind::Percent)
+                }
+            }
             Some('.') => {
                 let start = self.position;
                 if self.peek_char() == Some('.') {
@@ -1003,4 +1025,58 @@ mod tests {
             assert_eq!(kind, expected);
         }
     }
+
+    #[test]
+    fn test_lex_times_equals() {
+        let code = "x *= 10;";
+        let mut lexer = Lexer::new(code);
+        let expected_tokens = vec![
+            TokenKind::Identifier("x".to_string()),
+            TokenKind::StarEquals,
+            TokenKind::Int(10),
+            TokenKind::Semicolon,
+            TokenKind::Eof,
+        ];
+
+        for expected in expected_tokens {
+            let kind = lexer.next_token().kind;
+            assert_eq!(kind, expected);
+        }
+    }
+
+    #[test]
+    fn test_lex_divide_equals() {
+        let code = "x /= 10;";
+        let mut lexer = Lexer::new(code);
+        let expected_tokens = vec![
+            TokenKind::Identifier("x".to_string()),
+            TokenKind::SlashEquals,
+            TokenKind::Int(10),
+            TokenKind::Semicolon,
+            TokenKind::Eof,
+        ];
+
+        for expected in expected_tokens {
+            let kind = lexer.next_token().kind;
+            assert_eq!(kind, expected);
+        }
+    }
+
+    #[test]
+    fn test_lex_mod_equals() {
+        let code = "x %= 10;";
+        let mut lexer = Lexer::new(code);
+        let expected_tokens = vec![
+            TokenKind::Identifier("x".to_string()),
+            TokenKind::PercentEquals,
+            TokenKind::Int(10),
+            TokenKind::Semicolon,
+            TokenKind::Eof,
+        ];
+
+        for expected in expected_tokens {
+            let kind = lexer.next_token().kind;
+            assert_eq!(kind, expected);
+        }
+    }
 }
diff --git a/src/parser.rs b/src/parser.rs
index 1443fdc..84e3230 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -286,6 +286,7 @@ pub enum Operator {
     Multiply,
     Divide,
     Equals,
+    Modulo,
 }
 
 pub struct Parser {
@@ -828,10 +829,17 @@ impl Parser {
 
         loop {
             match self.current_token().kind {
-                TokenKind::PlusEquals | TokenKind::MinusEquals => {
+                TokenKind::PlusEquals
+                | TokenKind::MinusEquals
+                | TokenKind::StarEquals
+                | TokenKind::SlashEquals
+                | TokenKind::PercentEquals => {
                     let op = match self.current_token().kind {
                         TokenKind::PlusEquals => Operator::Plus,
                         TokenKind::MinusEquals => Operator::Minus,
+                        TokenKind::StarEquals => Operator::Multiply,
+                        TokenKind::SlashEquals => Operator::Divide,
+                        TokenKind::PercentEquals => Operator::Modulo,
                         _ => unreachable!(),
                     };
                     self.advance();
diff --git a/tests/scripts/opers.hk b/tests/scripts/opers.hk
new file mode 100644
index 0000000..a9038b6
--- /dev/null
+++ b/tests/scripts/opers.hk
@@ -0,0 +1,20 @@
+let a = 1;
+a += 8;
+println(a);
+
+a -= 3;
+println(a);
+
+a *= 2;
+println(a);
+
+a /= 2;
+println(a);
+
+a %= 2;
+println(a);
+
+a += 1;
+
+a %= 2;
+println(a);
diff --git a/tests/scripts/opers.hk.err b/tests/scripts/opers.hk.err
new file mode 100644
index 0000000..e69de29
diff --git a/tests/scripts/opers.hk.out b/tests/scripts/opers.hk.out
new file mode 100644
index 0000000..0638fa8
--- /dev/null
+++ b/tests/scripts/opers.hk.out
@@ -0,0 +1,6 @@
+9
+6
+12
+6
+0
+1