diff --git a/src/gui/math3d/qmatrix4x4.cpp b/src/gui/math3d/qmatrix4x4.cpp
index 4e35d49118..d8c2116b0d 100644
--- a/src/gui/math3d/qmatrix4x4.cpp
+++ b/src/gui/math3d/qmatrix4x4.cpp
@@ -45,6 +45,8 @@
 #include <QtGui/qmatrix.h>
 #include <QtGui/qtransform.h>
 
+#include <cmath>
+
 QT_BEGIN_NAMESPACE
 
 #ifndef QT_NO_MATRIX4X4
diff --git a/src/gui/math3d/qquaternion.cpp b/src/gui/math3d/qquaternion.cpp
index 3f39fa43c3..2ccdd315d3 100644
--- a/src/gui/math3d/qquaternion.cpp
+++ b/src/gui/math3d/qquaternion.cpp
@@ -45,6 +45,8 @@
 #include <QtCore/qvariant.h>
 #include <QtCore/qdebug.h>
 
+#include <cmath>
+
 QT_BEGIN_NAMESPACE
 
 #ifndef QT_NO_QUATERNION