diff --git a/include/libcamera/geometry.h b/include/libcamera/geometry.h
index 2f3a82e2afc3..0a9d61f45874 100644
--- a/include/libcamera/geometry.h
+++ b/include/libcamera/geometry.h
@@ -92,8 +92,8 @@ public:
 		return *this;
 	}
 
-	constexpr Size alignedDownTo(unsigned int hAlignment,
-				     unsigned int vAlignment) const
+	[[nodiscard]] constexpr Size alignedDownTo(unsigned int hAlignment,
+						   unsigned int vAlignment) const
 	{
 		return {
 			width / hAlignment * hAlignment,
@@ -101,8 +101,8 @@ public:
 		};
 	}
 
-	constexpr Size alignedUpTo(unsigned int hAlignment,
-				   unsigned int vAlignment) const
+	[[nodiscard]] constexpr Size alignedUpTo(unsigned int hAlignment,
+						 unsigned int vAlignment) const
 	{
 		return {
 			(width + hAlignment - 1) / hAlignment * hAlignment,
@@ -110,7 +110,7 @@ public:
 		};
 	}
 
-	constexpr Size boundedTo(const Size &bound) const
+	[[nodiscard]] constexpr Size boundedTo(const Size &bound) const
 	{
 		return {
 			std::min(width, bound.width),
@@ -118,7 +118,7 @@ public:
 		};
 	}
 
-	constexpr Size expandedTo(const Size &expand) const
+	[[nodiscard]] constexpr Size expandedTo(const Size &expand) const
 	{
 		return {
 			std::max(width, expand.width),
@@ -126,10 +126,10 @@ public:
 		};
 	}
 
-	Size boundedToAspectRatio(const Size &ratio) const;
-	Size expandedToAspectRatio(const Size &ratio) const;
+	[[nodiscard]] Size boundedToAspectRatio(const Size &ratio) const;
+	[[nodiscard]] Size expandedToAspectRatio(const Size &ratio) const;
 
-	Rectangle centeredTo(const Point &center) const;
+	[[nodiscard]] Rectangle centeredTo(const Point &center) const;
 
 	Size operator*(float factor) const;
 	Size operator/(float factor) const;
@@ -247,10 +247,11 @@ public:
 	Rectangle &scaleBy(const Size &numerator, const Size &denominator);
 	Rectangle &translateBy(const Point &point);
 
-	Rectangle boundedTo(const Rectangle &bound) const;
-	Rectangle enclosedIn(const Rectangle &boundary) const;
-	Rectangle scaledBy(const Size &numerator, const Size &denominator) const;
-	Rectangle translatedBy(const Point &point) const;
+	[[nodiscard]] Rectangle boundedTo(const Rectangle &bound) const;
+	[[nodiscard]] Rectangle enclosedIn(const Rectangle &boundary) const;
+	[[nodiscard]] Rectangle scaledBy(const Size &numerator,
+					 const Size &denominator) const;
+	[[nodiscard]] Rectangle translatedBy(const Point &point) const;
 };
 
 bool operator==(const Rectangle &lhs, const Rectangle &rhs);