diff --git a/include/libcamera/geometry.h b/include/libcamera/geometry.h
index d9378efeca8c..572a07e2cf92 100644
--- a/include/libcamera/geometry.h
+++ b/include/libcamera/geometry.h
@@ -108,6 +108,12 @@ public:
 		return *this;
 	}
 
+	Size &transpose()
+	{
+		std::swap(width, height);
+		return *this;
+	}
+
 	[[nodiscard]] constexpr Size alignedDownTo(unsigned int hAlignment,
 						   unsigned int vAlignment) const
 	{
diff --git a/src/libcamera/geometry.cpp b/src/libcamera/geometry.cpp
index de76d0c12a8c..2763967a6e57 100644
--- a/src/libcamera/geometry.cpp
+++ b/src/libcamera/geometry.cpp
@@ -209,6 +209,16 @@ std::string Size::toString() const
  * \return A reference to this object
  */
 
+/**
+ * \fn Size::transpose()
+ * \brief Transpose the size in place
+ *
+ * This function swaps width and height of this size. This effectively applies
+ * the \a Transform::Transpose transformation on this size.
+ *
+ * \return A reference to this object
+ */
+
 /**
  * \fn Size::alignedDownTo(unsigned int hAlignment, unsigned int vAlignment)
  * \brief Align the size down horizontally and vertically