diff --git a/src/rpn.rs b/src/rpn.rs
index 83af537..893266f 100644
--- a/src/rpn.rs
+++ b/src/rpn.rs
@@ -50,7 +50,7 @@ use std::{
 	process::ExitCode,
 };
 
-use CalcType::{ Add, Divide, Multiply, Power, Subtract, Val };
+use CalcType::{ Add, Divide, Modulo, Multiply, Power, Subtract, Val };
 
 extern crate sysexits;
 
@@ -64,6 +64,7 @@ enum CalcType {
 	Multiply,
 	Divide,
 	Power,
+	Modulo,
 	Val(f64),
 }
 
@@ -100,6 +101,7 @@ fn str_to_calc_type(string: &str) -> Option<CalcType> {
 		"*" => Some(Multiply),
 		"/" => Some(Divide),
 		"^" => Some(Power),
+		"%" => Some(Modulo),
 		_ => None,
 	}
 }
@@ -130,15 +132,16 @@ fn eval(
 		};
 
 		match x {
-			Add | Divide | Multiply | Power | Subtract => ops.push_back(x),
-
+			Add | Divide | Multiply | Power | Subtract | Modulo => {
+				ops.push_back(x)
+			},
 			Val(x_) => stack.push_back(x_),
 		}
 	}
 
 	for op in &ops {
 		match op {
-			Add | Subtract | Multiply | Divide | Power => {
+			Add | Subtract | Multiply | Divide | Power | Modulo => {
 				let x = &stack.pop_back().ok_or(EvaluationError {
 					message: "Stack is empty.".to_string(),
 				})?;
@@ -148,22 +151,12 @@ fn eval(
 				})?;
 
 				match op {
-					Add => {
-						&stack.push_back(y + x)
-					},
-					Subtract => {
-						&stack.push_back(y - x)
-					},
-					Multiply => {
-						&stack.push_back(y * x)
-					},
-					Divide => {
-						&stack.push_back(y / x)
-					},
-					Power => {
-						let result = x.powf(*y);
-						&stack.push_back(result)
-					},
+					Add => &stack.push_back(y + x),
+					Subtract => &stack.push_back(y - x),
+					Multiply => &stack.push_back(y * x),
+					Divide => &stack.push_back(y / x),
+					Power => &stack.push_back(x.powf(*y)),
+					Modulo => &stack.push_back(y % x),
 					_ => &{},
 				};
 			},