diff --git a/CMakeLists.txt b/CMakeLists.txt
index 10fb1e396..3c1bedfee 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1401,8 +1401,10 @@ else (${OPENMP_FOUND} OR APPLE)
   target_link_libraries (jt9 wsjt_fort wsjt_cxx fort_qt)
 endif (${OPENMP_FOUND} OR APPLE)
 
-# build map65
-add_subdirectory (map65)
+if (WIN32)
+  # build map65
+  add_subdirectory (map65)
+endif ()
 
 # build the main application
 generate_version_info (wsjtx_VERSION_RESOURCES
diff --git a/map65/libm65/extract.f90 b/map65/libm65/extract.f90
index 677bf57f8..4d8af58a9 100644
--- a/map65/libm65/extract.f90
+++ b/map65/libm65/extract.f90
@@ -98,7 +98,7 @@ subroutine extract(s3,nadd,ncount,nhist,decoded,ltext)
        itmp(i)=correct(64-i)
      enddo
      correct(1:63)=itmp(1:63)
-     call interleave63(correct,63,1)
+     call interleave63(correct,1)
      call graycode65(correct,63,1)
      call unpackmsg(dat4,decoded)     !Unpack the user message
      ncount=0
@@ -120,7 +120,7 @@ subroutine getpp(workdat,p)
 
   a(1:63)=workdat(63:1:-1)
   call interleave63(a,1)
-  call graycode(a,63,1,a)
+  call graycode(a,63,1)
 
   psum=0.
   do j=1,63
diff --git a/map65/plotter.h b/map65/plotter.h
index 6f2922458..36f0bcd0f 100644
--- a/map65/plotter.h
+++ b/map65/plotter.h
@@ -24,8 +24,8 @@ public:
   explicit CPlotter(QWidget *parent = 0);
   ~CPlotter();
 
-  QSize minimumSizeHint() const;
-  QSize sizeHint() const;
+  QSize minimumSizeHint() const override;
+  QSize sizeHint() const override;
   QColor  m_ColorTbl[256];
   bool    m_bDecodeFinished;
   int     m_plotZero;
@@ -81,8 +81,8 @@ signals:
 
 protected:
   //re-implemented widget event handlers
-  void paintEvent(QPaintEvent *event);
-  void resizeEvent(QResizeEvent* event);
+  void paintEvent(QPaintEvent *event) override;
+  void resizeEvent(QResizeEvent* event) override;
   void mouseMoveEvent(QMouseEvent * event) override;
 
 private:
@@ -132,8 +132,8 @@ private:
   qint32  m_TxDF;
 
 private slots:
-  void mousePressEvent(QMouseEvent *event);
-  void mouseDoubleClickEvent(QMouseEvent *event);
+  void mousePressEvent(QMouseEvent *event) override;
+  void mouseDoubleClickEvent(QMouseEvent *event) override;
 };
 
 #endif // PLOTTER_H