diff --git a/complex.hh b/complex.hh
index 00f6e68..d4dce63 100644
--- a/complex.hh
+++ b/complex.hh
@@ -6,6 +6,8 @@ Copyright 2018 Ahmet Inan <inan@aicodix.de>
 
 #pragma once
 
+namespace DSP {
+
 template <typename T>
 class Complex
 {
@@ -118,3 +120,5 @@ static constexpr T arg(Complex<T> a)
 	return atan2(a.imag(), a.real());
 }
 
+}
+