diff --git a/lang/src/ast.asm b/lang/src/ast.asm
index 3e735b9..5c011da 100644
--- a/lang/src/ast.asm
+++ b/lang/src/ast.asm
@@ -20,6 +20,12 @@ section .rdata
     TYPE_STR equ 5
 ;; end-consts
 
+    PRECEDENCE_ADD equ 90
+    PRECEDENCE_SUB equ 90
+    PRECEDENCE_MUL equ 100
+    PRECEDENCE_DIV equ 100
+    PRECEDENCE_REM equ 100
+
 section .text
 extern vec_init_with
 extern vec_push
@@ -323,7 +329,8 @@ parse_binary_expr:
     sub rsp, 64
     ; lexeme: Lexeme [32..56]
     ; right: u64 [24..32]
-    ; precedence: u8 [17..18]
+    ; our_precedence: u8 [18..19]
+    ; upper_precedence: u8 [17..18]
     ; operator: u8 [16..17]
     ; left: u64 [8..16]
     ; rdi: *mut Ast [0..8]
@@ -339,22 +346,49 @@ parse_binary_expr:
     lea rdi, [rsp + 32]         ; lexeme
     call peek_lexeme
     mov rax, [rsp + 32]
-    mov dil, [rsp + 17]
-    cmp al, dil          ; our_precedence <= upper_precedence
-    jle .done            ; also covers some non-binary operator tokens
     cmp al, TOKEN_PLUS
-    je .plus
+    je .add
+    cmp al, TOKEN_MINUS
+    je .sub
+    cmp al, TOKEN_STAR
+    je .mul
+    cmp al, TOKEN_SLASH
+    je .div
     jmp .done
 
-.plus:
+.add:
     mov dil, TOKEN_PLUS
     call unwrap_token
     mov byte [rsp + 16], TOKEN_PLUS
+    mov byte [rsp + 18], PRECEDENCE_ADD
+    jmp .right
+.sub:
+    mov dil, TOKEN_MINUS
+    call unwrap_token
+    mov byte [rsp + 16], TOKEN_MINUS
+    mov byte [rsp + 18], PRECEDENCE_SUB
+    jmp .right
+.mul:
+    mov dil, TOKEN_STAR
+    call unwrap_token
+    mov byte [rsp + 16], TOKEN_STAR
+    mov byte [rsp + 18], PRECEDENCE_MUL
+    jmp .right
+.div:
+    mov dil, TOKEN_SLASH
+    call unwrap_token
+    mov byte [rsp + 16], TOKEN_SLASH
+    mov byte [rsp + 18], PRECEDENCE_DIV
     jmp .right
 
 .right:
+    mov dil, [rsp + 17]
+    mov al, [rsp + 18]          ; our_precedence
+    cmp al, dil                 ; our_precedence <= upper_precedence
+    jle .done
+
     mov rdi, [rsp]         ; Ast
-    mov sil, [rsp + 16]
+    mov sil, [rsp + 18]
     call parse_binary_expr
     mov [rsp + 24], rax             ; right
 
diff --git a/lang/tests/ast.rs b/lang/tests/ast.rs
index 13e39b9..594b03b 100644
--- a/lang/tests/ast.rs
+++ b/lang/tests/ast.rs
@@ -37,6 +37,15 @@ fn main() {
     print_ast(b"fn main() -> void { return (1 + (2)); }", |ast| unsafe {
         parse_func(ast);
     });
+    print_ast(
+        b"fn main() -> void { return (1 + (2 * 3)) / 4; }",
+        |ast| unsafe {
+            parse_func(ast);
+        },
+    );
+    print_ast(b"fn main() -> void { return 1 + 2 * 3; }", |ast| unsafe {
+        parse_func(ast);
+    });
 }
 
 impl std::fmt::Display for AstNode {
diff --git a/lang/tests/tokens.rs b/lang/tests/tokens.rs
index 1eb53a5..7c9a6d1 100644
--- a/lang/tests/tokens.rs
+++ b/lang/tests/tokens.rs
@@ -176,7 +176,7 @@ fn main() {
 
         assert_eq!(expect_token(2).into_option(), None);
         assert_eq!(expect_token(4).into_option().unwrap().as_str(), "fn");
-        assert_eq!(unwrap_token(31).as_str(), "my-function");
+        assert_eq!(unwrap_token(TOKEN_IDENT).as_str(), "my-function");
 
         eprint!("Initializing tokeniser.. ");
         tokeniser_init(c"tests/tokens/comment.l".as_ptr());
@@ -185,7 +185,7 @@ fn main() {
         assert_eq!(
             &collect_tokens()[..],
             &[
-                Lexeme(34, ""),
+                Lexeme(TOKEN_COMMENT, ""),
                 Lexeme(4, ""),
                 Lexeme(TOKEN_IDENT, "my-function"),
                 Lexeme(19, ""),
@@ -193,7 +193,7 @@ fn main() {
                 Lexeme(12, ""),
                 Lexeme(11, ""),
                 Lexeme(21, ""),
-                Lexeme(34, ""),
+                Lexeme(TOKEN_COMMENT, ""),
                 Lexeme(5, ""),
                 Lexeme(10, ""),
                 Lexeme(23, ""),
@@ -223,11 +223,14 @@ fn main() {
         assert_eq!(
             &collect_tokens()[..],
             &[
-                Lexeme(TOKEN_COMMENT, "\"this is a string\""),
-                Lexeme(TOKEN_COMMENT, "\"another\nstring\nspanning multiple\n   lines\""),
-                Lexeme(TOKEN_COMMENT, "\"string with a \\\"quoted\\\" word\""),
-                Lexeme(TOKEN_COMMENT, "\"a\""),
-                Lexeme(TOKEN_COMMENT, "\"\"")
+                Lexeme(TOKEN_STRING, "\"this is a string\""),
+                Lexeme(
+                    TOKEN_STRING,
+                    "\"another\nstring\nspanning multiple\n   lines\""
+                ),
+                Lexeme(TOKEN_STRING, "\"string with a \\\"quoted\\\" word\""),
+                Lexeme(TOKEN_STRING, "\"a\""),
+                Lexeme(TOKEN_STRING, "\"\"")
             ],
         );
 
@@ -238,7 +241,11 @@ fn main() {
 
         assert_eq!(
             &collect_tokens()[..],
-            &[Lexeme(TOKEN_NUMBER, "3"), Lexeme(16, "+"), Lexeme(TOKEN_NUMBER, "4")],
+            &[
+                Lexeme(TOKEN_NUMBER, "3"),
+                Lexeme(16, "+"),
+                Lexeme(TOKEN_NUMBER, "4")
+            ],
         );
 
         eprint!("Initializing tokeniser.. ");
@@ -265,6 +272,27 @@ fn main() {
             ],
         );
 
+        eprint!("Initializing tokeniser.. ");
+        let src = b"(b / d + c) * 42;";
+        tokeniser_init_buf(src.as_ptr(), src.len());
+        eprintln!("ok.");
+
+        assert_eq!(
+            &collect_tokens()[..],
+            &[
+                Lexeme(19, "("),
+                Lexeme(33, "b"),
+                Lexeme(31, "/"),
+                Lexeme(33, "d"),
+                Lexeme(16, "+"),
+                Lexeme(33, "c"),
+                Lexeme(18, ")"),
+                Lexeme(32, "*"),
+                Lexeme(34, "42"),
+                Lexeme(23, ";")
+            ],
+        );
+
         eprintln!("Finished tokenising.");
     }
 }