diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index d93df28b20b..8915606f235 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -5031,7 +5031,7 @@ module ts {
                         error(node, Diagnostics.The_0_operator_is_not_allowed_for_boolean_types_Consider_using_1_instead, tokenToString(node.operator), tokenToString(suggestedOperator));
                     }
                     else {
-                        // otherwise just check each operand seperately and report errors as normal 
+                        // otherwise just check each operand separately and report errors as normal 
                         var leftOk = checkArithmeticOperandType(node.left, leftType, Diagnostics.The_left_hand_side_of_an_arithmetic_operation_must_be_of_type_any_number_or_an_enum_type);
                         var rightOk = checkArithmeticOperandType(node.right, rightType, Diagnostics.The_right_hand_side_of_an_arithmetic_operation_must_be_of_type_any_number_or_an_enum_type);
                         if (leftOk && rightOk) {