diff --git a/include/Nazara/Utility/IndexIterator.hpp b/include/Nazara/Utility/IndexIterator.hpp
index ee3cfdc41..d989f90fb 100644
--- a/include/Nazara/Utility/IndexIterator.hpp
+++ b/include/Nazara/Utility/IndexIterator.hpp
@@ -28,8 +28,8 @@ class NzIndexIterator
 
 		NzIndexIterator& operator=(const NzIndexIterator& iterator);
 
-		NzIndexIterator operator+(unsigned int indexCount);
-		NzIndexIterator operator-(unsigned int indexCount);
+		NzIndexIterator operator+(unsigned int indexCount) const;
+		NzIndexIterator operator-(unsigned int indexCount) const;
 
 		NzIndexIterator& operator+=(unsigned int indexCount);
 		NzIndexIterator& operator-=(unsigned int indexCount);
diff --git a/include/Nazara/Utility/IndexIterator.inl b/include/Nazara/Utility/IndexIterator.inl
index 83530652a..d7def8d59 100644
--- a/include/Nazara/Utility/IndexIterator.inl
+++ b/include/Nazara/Utility/IndexIterator.inl
@@ -41,12 +41,12 @@ inline NzIndexIterator& NzIndexIterator::operator=(const NzIndexIterator& iterat
 	return *this;
 }
 
-inline NzIndexIterator NzIndexIterator::operator+(unsigned int indexCount)
+inline NzIndexIterator NzIndexIterator::operator+(unsigned int indexCount) const
 {
 	return NzIndexIterator(m_mapper, m_index + indexCount);
 }
 
-inline NzIndexIterator NzIndexIterator::operator-(unsigned int indexCount)
+inline NzIndexIterator NzIndexIterator::operator-(unsigned int indexCount) const
 {
 	return NzIndexIterator(m_mapper, m_index - indexCount);
 }