diff -r 7cbdaefda950 -r ec691d9472b3 src/types/matrix.h
--- a/src/types/matrix.h	Sat Mar 03 17:59:56 2018 +0200
+++ b/src/types/matrix.h	Mon Mar 05 22:40:34 2018 +0200
@@ -59,6 +59,8 @@
 	double m_values[9];
 };
 
+Q_DECLARE_METATYPE(Matrix)
+
 /*
  * A structure that provides a view into a row in a matrix.
  * This is returned by operator[] so that the matrix can be accessed by A[i][j]