diff --git a/src/parser/ast.rs b/src/parser/ast.rs
index 35bfca5..af4f8b8 100644
--- a/src/parser/ast.rs
+++ b/src/parser/ast.rs
@@ -12,6 +12,14 @@ pub enum TypeExpr {
     Identifier(String),
 }
 
+#[derive(Debug, Clone, Serialize)]
+pub enum BinaryOp {
+    Plus,
+    Minus,
+    Multiply,
+    Divide,
+}
+
 #[derive(Debug, Clone, Serialize)]
 #[serde(tag = "type", content = "value")]
 pub enum TopLevel {
@@ -34,7 +42,9 @@ pub enum TopLevel {
 #[serde(tag = "type", content = "value")]
 pub enum Postfix {
     FieldAccess(String),
-    FunctionCall(Vec<Expression>),
+    Call(Vec<Expression>),
+    Index(Expression),
+    Binary(BinaryOp, Expression),
 }
 
 #[derive(Debug, Clone, Serialize)]
diff --git a/src/parser/grammar.pest b/src/parser/grammar.pest
index a91c38d..08824db 100644
--- a/src/parser/grammar.pest
+++ b/src/parser/grammar.pest
@@ -95,13 +95,18 @@ primary = {
 }
 
 postfix = {
-    ("." ~ identifier)
-  | ("(" ~ (expr ~ ("," ~ expr)*)? ~ ")")
-  | ("[" ~ expr ~ "]")
-  | ("++" | "--")
-  | (("+" | "-" | "*" | "/" | "%") ~ primary)
+    field_px
+  | call_px
+  | index_px
+  | binary_px
 }
 
+field_px  = { "." ~ identifier }
+call_px   = { "(" ~ (expr ~ ("," ~ expr)*)? ~ ")" }
+index_px  = { "[" ~ expr ~ "]" }
+binary_px = { bin_op ~ expr }
+bin_op = { "+" | "-" | "*" | "/" | "%" }
+
 expr = {
     primary ~ postfix*
 }
diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index f5e2e1e..6b14585 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -320,18 +320,34 @@ impl Expression {
 impl Postfix {
     pub fn from_pair(pair: pest::iterators::Pair<Rule>) -> Self {
         match pair.as_rule() {
-            Rule::postfix => {
-                let inner = pair.into_inner();
-                if let Some(field) = inner.peek() {
-                    if field.as_rule() == Rule::identifier {
-                        Postfix::FieldAccess(field.as_str().to_string())
-                    } else {
-                        Postfix::FunctionCall(inner.map(|p| Expression::from_pair(p)).collect())
-                    }
-                } else {
-                    Postfix::FunctionCall(vec![])
-                }
+            Rule::postfix => Postfix::from_pair(pair.into_inner().next().unwrap()),
+
+            Rule::field_px => {
+                let field_name = pair.into_inner().next().unwrap().as_str().to_string();
+                Postfix::FieldAccess(field_name)
             }
+
+            Rule::call_px => Postfix::Call(pair.into_inner().map(Expression::from_pair).collect()),
+
+            Rule::index_px => {
+                Postfix::Index(Expression::from_pair(pair.into_inner().next().unwrap()))
+            }
+
+            Rule::binary_px => {
+                let mut inner = pair.into_inner();
+                let op_pair = inner.next().unwrap();
+                let op = match op_pair.as_str() {
+                    "+" => BinaryOp::Plus,
+                    "-" => BinaryOp::Minus,
+                    "*" => BinaryOp::Multiply,
+                    "/" => BinaryOp::Divide,
+                    _ => {
+                        unimplemented!("Binary operator not implemented yet: {}", op_pair.as_str())
+                    }
+                };
+                Postfix::Binary(op, Expression::from_pair(inner.next().unwrap()))
+            }
+
             _ => unimplemented!("Postfix parsing not implemented yet {:?}", pair.as_rule()),
         }
     }