diff --git a/src/Mod/Part/Gui/TaskOffset.cpp b/src/Mod/Part/Gui/TaskOffset.cpp
index d32e6a47eb..8530ce5ab3 100644
--- a/src/Mod/Part/Gui/TaskOffset.cpp
+++ b/src/Mod/Part/Gui/TaskOffset.cpp
@@ -55,7 +55,7 @@ class OffsetWidget::Private
 public:
     Ui_TaskOffset ui;
     Part::Offset* offset;
-    Private()
+    Private() : offset(nullptr)
     {
     }
     ~Private()
diff --git a/src/Mod/Part/Gui/TaskThickness.cpp b/src/Mod/Part/Gui/TaskThickness.cpp
index 269257962a..f907687fdd 100644
--- a/src/Mod/Part/Gui/TaskThickness.cpp
+++ b/src/Mod/Part/Gui/TaskThickness.cpp
@@ -60,7 +60,7 @@ public:
     QString text;
     std::string selection;
     Part::Thickness* thickness;
-    Private()
+    Private() : thickness(nullptr)
     {
     }
     ~Private()
diff --git a/src/Mod/Path/PathSimulator/App/VolSim.h b/src/Mod/Path/PathSimulator/App/VolSim.h
index 8d448c8743..39fb371adf 100644
--- a/src/Mod/Path/PathSimulator/App/VolSim.h
+++ b/src/Mod/Path/PathSimulator/App/VolSim.h
@@ -74,7 +74,7 @@ struct Triangle3D
 
 struct cLineSegment
 {
-	cLineSegment() {}
+	cLineSegment() : len(0), lenXY(0) {}
 	cLineSegment(Point3D & p1, Point3D & p2) { SetPoints(p1, p2); }
 	void SetPoints(Point3D & p1, Point3D & p2);
 	void PointAt(float dist, Point3D & retp); 
@@ -93,7 +93,7 @@ public:
 		CHAMFER,
 		ROUND
 	};
-	cSimTool() {}
+	cSimTool() : type(FLAT), radius(0), tipAngle(0), dradius(0), chamRatio(0) {}
 	cSimTool(Type t, float rad, float tipang = 180) : type(t), radius(rad), tipAngle(tipang) { InitTool(); }
 	~cSimTool() {}
 	void InitTool();
diff --git a/src/Mod/Path/libarea/Adaptive.cpp b/src/Mod/Path/libarea/Adaptive.cpp
index dbd1cde03a..adb0389020 100644
--- a/src/Mod/Path/libarea/Adaptive.cpp
+++ b/src/Mod/Path/libarea/Adaptive.cpp
@@ -1134,14 +1134,14 @@ class EngagePoint
   public:
 	struct EngageState
 	{
-		size_t currentPathIndex;
-		size_t currentSegmentIndex;
+		size_t currentPathIndex = 0;
+		size_t currentSegmentIndex = 0;
 		double segmentPos = 0;
 		double totalDistance = 0;
 		double currentPathLength = 0;
 		int passes = 0;
 
-		double metric; // engage point metric
+		double metric = 0; // engage point metric
 
 		bool operator<(const EngageState &other) const
 		{
diff --git a/src/Mod/Path/libarea/kurve/geometry.h b/src/Mod/Path/libarea/kurve/geometry.h
index 85c6e23f68..326e8ad3bf 100644
--- a/src/Mod/Path/libarea/kurve/geometry.h
+++ b/src/Mod/Path/libarea/kurve/geometry.h
@@ -253,7 +253,7 @@ inline bool FNEZ(double a, double tolerance = TIGHT_TOLERANCE) {return fabs(a) >
 		double	z;																// z value
 
 		// constructors
-		inline	Point3d(){};// {z=0; /*ok=false;*/};												// Point p1
+		inline	Point3d(){x = 0; y = 0; z = 0;}// {z=0; /*ok=false;*/};												// Point p1
 		inline	Point3d(const double* xyz) {x = xyz[0], y = xyz[1]; z = xyz[2];}
 		inline	Point3d( double xord, double yord, double zord = 0/*, bool okay = true*/) {	// Point p1(10,30.5);
 			x = xord; y = yord; z = zord;/* ok = okay;*/}
@@ -296,7 +296,7 @@ inline bool FNEZ(double a, double tolerance = TIGHT_TOLERANCE) {return fabs(a) >
 	public:
 
 		// constructors
-		Vector2d() {};
+		inline	Vector2d() {dx = 0; dy = 0;}
 		inline	Vector2d(const Vector2d &v) { dx = v.dx; dy = v.dy;}
 				Vector2d(const Vector3d &v);		// careful
 		inline	Vector2d(double x, double y) {dx = x, dy = y;}
@@ -364,7 +364,7 @@ inline bool FNEZ(double a, double tolerance = TIGHT_TOLERANCE) {return fabs(a) >
 	public:
 
 		// constructors
-		Vector3d() {};
+		Vector3d() {dx = 0; dy = 0; dz = 0;}
 		Vector3d(const Vector3d &v) { dx = v.dx; dy = v.dy; dz = v.dz;}
 		Vector3d(double x, double y, double z = 0) {dx = x, dy = y; dz = z;}
 		Vector3d(const double* x) {dx = x[0], dy = x[1]; dz = x[2];}
@@ -440,7 +440,7 @@ inline bool FNEZ(double a, double tolerance = TIGHT_TOLERANCE) {return fabs(a) >
 		inline	CLine()	{ok = false;};
 		inline	CLine(const Point& p0, double dx, double dy, bool normalise = true){ p = p0; v = Vector2d(dx, dy); if(normalise) Normalise();};
 		inline	CLine(const Point& p0, const Vector2d& v0, bool normalise = true) {p = p0; v = v0; if(normalise) Normalise();};
-		inline	CLine( const CLine& s ) {p = s.p; v = s.v;};				// copy constructor  CLine s1(s2);
+		inline	CLine(const CLine& s) {p = s.p; v = s.v; ok = s.ok;}				// copy constructor  CLine s1(s2);
 		inline	CLine(const Point& p0, const Point& p1) {p = p0; v = Vector2d(p0, p1); Normalise();};
 		CLine(const Span& sp);	
 
@@ -477,7 +477,7 @@ inline bool FNEZ(double a, double tolerance = TIGHT_TOLERANCE) {return fabs(a) >
 		double	radius;
 
 		// constructors etc...
-		inline	Circle() {ok = false;};
+		inline	Circle() {ok = false; radius = 0;}
 		Circle( const Point& p, double r);										// Circle  c1(Point(10,30), 20);
 		Circle( const Point& p, const Point& pc);								// Circle  c1(p[222], p[223]);
 		Circle( const Circle& c ){*this = c;}									// copy constructor  Circle c1(c2);
@@ -590,7 +590,7 @@ inline bool FNEZ(double a, double tolerance = TIGHT_TOLERANCE) {return fabs(a) >
 		Vector2d GetVector(double fraction)const; // the direction along the span, 0.0 for start, 1.0 for end
 
 		// constructor
-		Span() {ID = 0; ok = false;};
+		Span() {dir = 0; ID = 0; ok = false; returnSpanProperties = false; length = 0; radius = 0; angle = 0; NullSpan = false;}
 		Span(int spandir, const Point& pn, const Point& pf, const Point& c) { dir = spandir; p0 = pn, p1 = pf, pc = c; ID = 0; SetProperties(true); ok = p0.ok;};
 
 		// operators
@@ -690,7 +690,7 @@ inline bool FNEZ(double a, double tolerance = TIGHT_TOLERANCE) {return fabs(a) >
 		double d;				// distance of plane to origin
 		Vector3d normal;				// normal to plane a = n.dx, b = n.dy, c = n.dz
 		// constructors
-		Plane(){ok = false;};
+		Plane(){ok = false; d = 0;}
 		Plane(double dist, const Vector3d& n);
 		Plane(const Point3d& p0, const Point3d& p1, const Point3d& p2);
 		Plane(const Point3d& p0, const Vector3d& n, bool normalise = true);
@@ -717,7 +717,7 @@ inline bool FNEZ(double a, double tolerance = TIGHT_TOLERANCE) {return fabs(a) >
 		int spanid;
 		Point p;
 		Point pc;
-		spVertex(){};
+		spVertex(){type = 0; spanid = 0;}
 		spVertex(int t, const Point& point, const Point& centre): type(t), spanid(0), p(point), pc(centre){};
 
 		bool operator==(spVertex &spv){
@@ -958,7 +958,7 @@ inline bool FNEZ(double a, double tolerance = TIGHT_TOLERANCE) {return fabs(a) >
 		bool ok;
 
 		// constructors
-		Line() {ok = false;};
+		Line() {ok = false; length = 0;}
 		Line(const Point3d& p0, const Vector3d& v0, bool boxed = true);
 		Line(const Point3d& p0, const Point3d& p1);
 		Line(const Span& sp);
diff --git a/src/Mod/TechDraw/Gui/QGICMark.cpp b/src/Mod/TechDraw/Gui/QGICMark.cpp
index 7180034021..3418ec6a1f 100644
--- a/src/Mod/TechDraw/Gui/QGICMark.cpp
+++ b/src/Mod/TechDraw/Gui/QGICMark.cpp
@@ -41,6 +41,7 @@ using namespace TechDrawGui;
 
 QGICMark::QGICMark(int index) : QGIVertex(index)
 {
+    projIndex = 0;
     m_size = 3.0;
     m_width = 0.75;
     draw();