diff --git a/common/camera.cpp b/common/camera.cpp
index 3be69de8..2fc88c35 100644
--- a/common/camera.cpp
+++ b/common/camera.cpp
@@ -871,7 +871,7 @@ void lcCamera::Orbit(float DistanceX, float DistanceY, const lcVector3& CenterPo
 	lcVector3 FrontVector(mPosition - mTargetPosition);
 
 	lcVector3 Z(lcNormalize(lcVector3(FrontVector[0], FrontVector[1], 0)));
-	if (isnan(Z[0]) || isnan(Z[1]))
+	if (qIsNaN(Z[0]) || qIsNaN(Z[1]))
 		Z = lcNormalize(lcVector3(mUpVector[0], mUpVector[1], 0));
 
 	if (mUpVector[2] < 0)
diff --git a/common/lc_global.h b/common/lc_global.h
index 088b475e..978ac2dc 100644
--- a/common/lc_global.h
+++ b/common/lc_global.h
@@ -31,7 +31,6 @@ typedef quintptr lcuintptr;
 
 #ifdef Q_OS_WIN
 #define snprintf _snprintf
-#define isnan _isnan
 #define strcasecmp stricmp
 #define strncasecmp strnicmp
 char* strcasestr(const char *s, const char *find);
diff --git a/qt/lc_qeditgroupsdialog.cpp b/qt/lc_qeditgroupsdialog.cpp
index 9f4c0558..4351358d 100644
--- a/qt/lc_qeditgroupsdialog.cpp
+++ b/qt/lc_qeditgroupsdialog.cpp
@@ -9,9 +9,10 @@
 #include "lc_basewindow.h"
 
 lcQEditGroupsDialog::lcQEditGroupsDialog(QWidget* Parent, const QMap<lcPiece*, lcGroup*>& PieceParents, const QMap<lcGroup*, lcGroup*>& GroupParents)
-	: QDialog(Parent), ui(new Ui::lcQEditGroupsDialog), mPieceParents(PieceParents), mGroupParents(GroupParents)
+	: QDialog(Parent), mPieceParents(PieceParents), mGroupParents(GroupParents)
 {
 	mLastItemClicked = NULL;
+	ui = new Ui::lcQEditGroupsDialog;
 
 	ui->setupUi(this);
 	connect(ui->treeWidget,SIGNAL(itemClicked(QTreeWidgetItem *,int)), this, SLOT(onItemClicked(QTreeWidgetItem *,int)));