diff --git a/patsolve/abstract_fc_solve_solver.h b/patsolve/abstract_fc_solve_solver.h
--- a/patsolve/abstract_fc_solve_solver.h
+++ b/patsolve/abstract_fc_solve_solver.h
@@ -25,19 +25,19 @@
 public:
     FcSolveSolver();
     virtual ~FcSolveSolver();
-    virtual int get_possible_moves(int *a, int *numout) = 0;
-    virtual bool isWon();
-    virtual void make_move(MOVE *m);
-    virtual void undo_move(MOVE *m);
-    virtual int getOuts();
-    virtual unsigned int getClusterNumber();
-    virtual void translate_layout() = 0;
-    virtual void unpack_cluster( unsigned int k );
-    virtual MoveHint translateMove(const MOVE &m) = 0;
-    virtual SolverInterface::ExitStatus patsolve( int _max_positions = -1);
+    virtual int get_possible_moves(int *a, int *numout) Q_DECL_OVERRIDE = 0;
+    virtual bool isWon() Q_DECL_OVERRIDE;
+    virtual void make_move(MOVE *m) Q_DECL_OVERRIDE;
+    virtual void undo_move(MOVE *m) Q_DECL_OVERRIDE;
+    virtual int getOuts() Q_DECL_OVERRIDE;
+    virtual unsigned int getClusterNumber() Q_DECL_OVERRIDE;
+    virtual void translate_layout() Q_DECL_OVERRIDE = 0;
+    virtual void unpack_cluster( unsigned int k ) Q_DECL_OVERRIDE;
+    virtual MoveHint translateMove(const MOVE &m) Q_DECL_OVERRIDE = 0;
+    virtual SolverInterface::ExitStatus patsolve( int _max_positions = -1) Q_DECL_OVERRIDE;
     virtual void setFcSolverGameParams() = 0;
 
-    virtual void print_layout();
+    virtual void print_layout() Q_DECL_OVERRIDE;
 
     virtual int get_cmd_line_arg_count() = 0;
     virtual const char * * get_cmd_line_args() = 0;
diff --git a/patsolve/freecellsolver.h b/patsolve/freecellsolver.h
--- a/patsolve/freecellsolver.h
+++ b/patsolve/freecellsolver.h
@@ -42,14 +42,14 @@
     void unpack_cluster( unsigned int k ) Q_DECL_OVERRIDE;
     MoveHint translateMove(const MOVE &m) Q_DECL_OVERRIDE;
 #endif
-    virtual void translate_layout();
+    virtual void translate_layout() Q_DECL_OVERRIDE;
 #if 0
     virtual void unpack_cluster( unsigned int k );
 #endif
-    virtual MoveHint translateMove(const MOVE &m);
-    virtual void setFcSolverGameParams();
-    virtual int get_cmd_line_arg_count();
-    virtual const char * * get_cmd_line_args();
+    virtual MoveHint translateMove(const MOVE &m) Q_DECL_OVERRIDE;
+    virtual void setFcSolverGameParams() Q_DECL_OVERRIDE;
+    virtual int get_cmd_line_arg_count() Q_DECL_OVERRIDE;
+    virtual const char * * get_cmd_line_args() Q_DECL_OVERRIDE;
 #if 0
     virtual void print_layout();
 
diff --git a/patsolve/golfsolver.h b/patsolve/golfsolver.h
--- a/patsolve/golfsolver.h
+++ b/patsolve/golfsolver.h
@@ -33,7 +33,7 @@
 #ifdef WITH_BH_SOLVER
     black_hole_solver_instance_t *solver_instance;
     int solver_ret;
-    SolverInterface::ExitStatus patsolve( int _max_positions );
+    SolverInterface::ExitStatus patsolve( int _max_positions ) Q_DECL_OVERRIDE;
     // More than enough space for two decks.
     char board_as_string[4 * 13 * 2 * 4 * 3];
     void free_solver_instance();
diff --git a/patsolve/patsolve.h b/patsolve/patsolve.h
--- a/patsolve/patsolve.h
+++ b/patsolve/patsolve.h
@@ -57,13 +57,13 @@
 
     Solver();
     virtual ~Solver();
-    virtual ExitStatus patsolve( int max_positions = -1);
+    virtual ExitStatus patsolve( int max_positions = -1) Q_DECL_OVERRIDE;
     bool recursive(POSITION *pos = nullptr);
-    virtual void translate_layout() = 0;
-    virtual MoveHint translateMove(const MOVE &m ) = 0;
-    void stopExecution() final;
-    QList<MOVE> firstMoves() const final;
-    QList<MOVE> winMoves() const final;
+    virtual void translate_layout() Q_DECL_OVERRIDE = 0;
+    virtual MoveHint translateMove(const MOVE &m ) Q_DECL_OVERRIDE = 0;
+    void stopExecution() final Q_DECL_OVERRIDE;
+    QList<MOVE> firstMoves() const final Q_DECL_OVERRIDE;
+    QList<MOVE> winMoves() const final Q_DECL_OVERRIDE;
 
 protected:
     MOVE *get_moves(int *nmoves);
diff --git a/patsolve/patsolve.cpp b/patsolve/patsolve.cpp
--- a/patsolve/patsolve.cpp
+++ b/patsolve/patsolve.cpp
@@ -166,7 +166,7 @@
 {
     	/* Make sure all the piles have id numbers. */
 
-	for (int w = 0; w < NumberPiles; w++) {
+	for (size_t w = 0; w < NumberPiles; w++) {
 		if (Wpilenum[w] < 0) {
 			Wpilenum[w] = get_pilenum(w);
 			if (Wpilenum[w] < 0) {
@@ -208,7 +208,7 @@
 template<size_t NumberPiles>
 TREE *Solver<NumberPiles>::pack_position(void)
 {
-	int j, w;
+	int j;
 	quint8 *p;
 	TREE *node;
 
@@ -232,7 +232,7 @@
 	*/
 
         quint16 *p2 = ( quint16* ) p;
-	for (w = 0; w < NumberPiles; ++w) {
+	for (size_t w = 0; w < NumberPiles; ++w) {
 		j = Wpilenum[w];
                 if ( j < 0 )
                 {
@@ -265,7 +265,7 @@
 template<size_t NumberPiles>
 void Solver<NumberPiles>::unpack_position(POSITION *pos)
 {
-	int i, w;
+	int i = 0;
 	BUCKETLIST *l;
 
         unpack_cluster(pos->cluster);
@@ -278,7 +278,7 @@
 		       j             j
 	*/
 
-	w = i = 0;
+	size_t w = 0;
 	quint16 *p2 = ( quint16* )( (quint8 *)(pos->node) + sizeof(TREE) );
 	while (w < NumberPiles) {
                 i = *p2++;
@@ -489,7 +489,6 @@
 	int i, q;
 	POSITION *pos;
 	MOVE m;
-        memset( &m, 0, sizeof( MOVE ) );
 
 	/* Init the queues. */
 
@@ -757,7 +756,7 @@
 template<size_t NumberPiles>
 Solver<NumberPiles>::~Solver()
 {
-    for ( int i = 0; i < NumberPiles; ++i )
+    for ( size_t i = 0; i < NumberPiles; ++i )
     {
         delete [] W[i];
     }
@@ -970,9 +969,7 @@
 template<size_t NumberPiles>
 void Solver<NumberPiles>::hash_layout(void)
 {
-	int w;
-
-	for (w = 0; w < NumberPiles; w++) {
+	for (size_t w = 0; w < NumberPiles; w++) {
 		hashpile(w);
 	}
 }
diff --git a/patsolve/simonsolver.h b/patsolve/simonsolver.h
--- a/patsolve/simonsolver.h
+++ b/patsolve/simonsolver.h
@@ -41,10 +41,10 @@
     void unpack_cluster( unsigned int k ) Q_DECL_OVERRIDE;
     void print_layout() Q_DECL_OVERRIDE;
 #endif
-    virtual void setFcSolverGameParams();
+    virtual void setFcSolverGameParams() Q_DECL_OVERRIDE;
 
-    virtual int get_cmd_line_arg_count();
-    virtual const char * * get_cmd_line_args();
+    virtual int get_cmd_line_arg_count() Q_DECL_OVERRIDE;
+    virtual const char * * get_cmd_line_args() Q_DECL_OVERRIDE;
 #if 0
 /* Names of the cards.  The ordering is defined in pat.h. */
     int O[4];
diff --git a/patsolve/simonsolver.cpp b/patsolve/simonsolver.cpp
--- a/patsolve/simonsolver.cpp
+++ b/patsolve/simonsolver.cpp
@@ -167,7 +167,7 @@
     freecell_solver_user_apply_preset(solver_instance, "simple_simon");
 }
 
-int SimonSolver::get_possible_moves(int *a, int *numout)
+int SimonSolver::get_possible_moves(int *, int *numout)
 {
     return (*numout = 0);
 }
diff --git a/patsolve/solverinterface.h b/patsolve/solverinterface.h
--- a/patsolve/solverinterface.h
+++ b/patsolve/solverinterface.h
@@ -31,7 +31,7 @@
         return pri < m.pri;
     }
 
-    MOVE() : is_fcs(false) {}
+    MOVE() :  card_index(0), from(0), to(0), totype(O_Type), pri(0), turn_index(0), is_fcs(false), fcs() {}
 };
 
 class SolverInterface {