diff --git a/src/Ast.hs b/src/Ast.hs
index 6253aa6..6554290 100644
--- a/src/Ast.hs
+++ b/src/Ast.hs
@@ -30,6 +30,7 @@ data BinaryOperator
   | Subtraction
   | Multiplication
   | Division
+  | Modulus
   | BitwiseAnd
   | BitwiseOr
   | BitwiseXor
diff --git a/src/Typecheck.hs b/src/Typecheck.hs
index 5f1f28c..7a7ac8d 100644
--- a/src/Typecheck.hs
+++ b/src/Typecheck.hs
@@ -82,6 +82,12 @@ typeCheckExpression (BinaryOperation op expr1 expr2) symtab classes =
               TypedExpression "int" (BinaryOperation op expr1' expr2')
             else
               error "Division operation requires two operands of type int"
+        Modulus ->
+          if type1 == "int" && type2 == "int"
+            then
+              TypedExpression "int" (BinaryOperation op expr1' expr2')
+            else
+              error "Modulus operation requires two operands of type int"
         BitwiseAnd ->
           if type1 == "int" && type2 == "int"
             then