diff --git a/docs/changes.txt b/docs/changes.txt
index 25d36877e0..840417ab50 100644
--- a/docs/changes.txt
+++ b/docs/changes.txt
@@ -54,6 +54,12 @@ Changes in behaviour not resulting in compilation errors
 - wxEVT_AUINOTEBOOK_PAGE_CHANGED event is now sent after changing the page,
   as expected, and not before doing it.
 
+- wxJoystickEvent::GetButtonChange() now returns "1 << N" for the events
+  generated by the button number N under all platforms, whereas it used to
+  return just "N" under Linux and macOS. Use the new GetButtonOrdinal() to
+  update the existing code if necessary.
+
+
 Changes in behaviour which may result in build errors
 -----------------------------------------------------
 
@@ -131,6 +137,7 @@ All (GUI):
 - Add wxGrid::SetCornerLabelValue() (Pavel Kalugin).
 - Add strikethrough support for fonts defined in XRC.
 - Add wxDisplay::GetPPI().
+- Add wxJoystickEvent::GetButtonOrdinal() (Mick Phillips).
 
 wxGTK:
 
diff --git a/include/wx/event.h b/include/wx/event.h
index d2b7a5d932..20f08b1ae2 100644
--- a/include/wx/event.h
+++ b/include/wx/event.h
@@ -15,6 +15,7 @@
 #include "wx/cpp.h"
 #include "wx/object.h"
 #include "wx/clntdata.h"
+#include "wx/math.h"
 
 #if wxUSE_GUI
     #include "wx/gdicmn.h"
@@ -2760,6 +2761,7 @@ public:
     int GetZPosition() const { return m_zPosition; }
     int GetButtonState() const { return m_buttonState; }
     int GetButtonChange() const { return m_buttonChange; }
+    int GetButtonOrdinal() const { return wxCTZ(m_buttonChange); }
     int GetJoystick() const { return m_joyStick; }
 
     void SetJoystick(int stick) { m_joyStick = stick; }
diff --git a/include/wx/math.h b/include/wx/math.h
index 544b5c7d6e..261969d364 100644
--- a/include/wx/math.h
+++ b/include/wx/math.h
@@ -150,6 +150,9 @@ inline int wxRound(double x)
 inline double wxDegToRad(double deg) { return (deg * M_PI) / 180.0; }
 inline double wxRadToDeg(double rad) { return (rad * 180.0) / M_PI; }
 
+// Count trailing zeros.
+WXDLLIMPEXP_BASE unsigned int wxCTZ(wxUint32 x);
+
 #endif /* __cplusplus */
 
 
diff --git a/interface/wx/event.h b/interface/wx/event.h
index b58fdc4a3c..061ba76201 100644
--- a/interface/wx/event.h
+++ b/interface/wx/event.h
@@ -1741,10 +1741,24 @@ public:
     /**
         Returns the identifier of the button changing state.
 
-        This is a @c wxJOY_BUTTONn identifier, where @c n is one of 1, 2, 3, 4.
+        The return value is @code 1 << n @endcode where @c n is the index of the
+        button changing state, which can also be retrieved using GetButtonOrdinal().
+
+        Note that for @c n equal to 1, 2, 3 or 4 there are predefined @c wxJOY_BUTTONn
+        constants which can be used for more clarity, however these constants are not
+        defined for the buttons beyond the first four.
     */
     int GetButtonChange() const;
 
+    /**
+        Returns the 0-indexed ordinal of the button changing state.
+
+        @see GetButtonChange()
+
+        @since 3.1.2.
+    */
+    int GetButtonOrdinal() const;
+
     /**
         Returns the down state of the buttons.
 
diff --git a/interface/wx/math.h b/interface/wx/math.h
index ca11a9fff2..b1486c270c 100644
--- a/interface/wx/math.h
+++ b/interface/wx/math.h
@@ -75,6 +75,19 @@ double wxDegToRad(double deg);
  */
 double wxRadToDeg(double rad);
 
+/**
+    Count the number of trailing zeros.
+
+    This function returns the number of trailing zeros in the binary notation
+    of its argument @a x. E.g. for @a x equal to 4, or 0b100, the return value
+    is 2.
+
+    @param x Strictly positive, i.e. non-zero, 32 bit number.
+
+    @since 3.1.2
+ */
+unsigned int wxCTZ(wxUint32 x);
+
 /**
     Small wrapper around round().
 */
diff --git a/samples/joytest/joytest.cpp b/samples/joytest/joytest.cpp
index dd62713eec..c355d05fe6 100644
--- a/samples/joytest/joytest.cpp
+++ b/samples/joytest/joytest.cpp
@@ -159,7 +159,7 @@ void MyCanvas::OnJoystickEvent(wxJoystickEvent& event)
 #if wxUSE_STATUSBAR
     wxString buf;
     if (event.ButtonDown())
-        buf.Printf("Joystick (%ld, %ld) #%i Fire!", xpos, ypos, event.GetButtonChange());
+        buf.Printf("Joystick (%ld, %ld) #%i Fire!", xpos, ypos, event.GetButtonOrdinal());
     else
         buf.Printf("Joystick (%ld, %ld)  ", xpos, ypos);
 
diff --git a/src/common/utilscmn.cpp b/src/common/utilscmn.cpp
index f18f5f1fb2..456dc1b38a 100644
--- a/src/common/utilscmn.cpp
+++ b/src/common/utilscmn.cpp
@@ -19,6 +19,8 @@
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
+#include "wx/debug.h"
+
 #ifdef __BORLANDC__
     #pragma hdrstop
 #endif
@@ -1015,6 +1017,27 @@ unsigned int wxGCD(unsigned int u, unsigned int v)
     return u << shift;
 }
 
+// ----------------------------------------------------------------------------
+// wxCTZ
+// Count trailing zeros. Use optimised builtin where available.
+// ----------------------------------------------------------------------------
+unsigned int wxCTZ(wxUint32 x)
+{
+    wxCHECK_MSG(x > 0, 0, "Undefined for x == 0.");
+#ifdef __GNUC__
+   return __builtin_ctz(x);
+#else
+   int n;
+   n = 1;
+   if ((x & 0x0000FFFF) == 0) {n = n +16; x = x >>16;}
+   if ((x & 0x000000FF) == 0) {n = n + 8; x = x >> 8;}
+   if ((x & 0x0000000F) == 0) {n = n + 4; x = x >> 4;}
+   if ((x & 0x00000003) == 0) {n = n + 2; x = x >> 2;}
+   return n - (x & 1);
+#endif
+}
+
+
 #endif // wxUSE_BASE
 
 // ============================================================================
diff --git a/src/msw/joystick.cpp b/src/msw/joystick.cpp
index 3290460ab6..b53aeb6d23 100644
--- a/src/msw/joystick.cpp
+++ b/src/msw/joystick.cpp
@@ -37,23 +37,6 @@
 
 #include <regstr.h>
 
-// Use optimised count trailing zeros where available.
-static int wxCtz(unsigned x)
-{
-    wxCHECK_MSG(x > 0, 0, "Undefined for x == 0.");
-#ifdef __GNUC__
-   return __builtin_ctz(x);
-#else
-   int n;
-   n = 1;
-   if ((x & 0x0000FFFF) == 0) {n = n +16; x = x >>16;}
-   if ((x & 0x000000FF) == 0) {n = n + 8; x = x >> 8;}
-   if ((x & 0x0000000F) == 0) {n = n + 4; x = x >> 4;}
-   if ((x & 0x00000003) == 0) {n = n + 2; x = x >> 2;}
-   return n - (x & 1);
-#endif
-}
-
 
 enum {
     wxJS_AXIS_X = 0,
@@ -90,7 +73,7 @@ public:
 private:
     void      SendEvent(wxEventType type, long ts, int change = 0);
     int       m_joystick;
-    UINT      m_buttons;
+    int       m_buttons;
     wxWindow* m_catchwin;
     int       m_polling;
     JOYINFO   m_joyInfo;
@@ -141,9 +124,9 @@ void* wxJoystickThread::Entry()
         // "Current button number that is pressed.", but it turns out
         // it is the *total* number of buttons pressed.
         if (deltaUp)
-            SendEvent(wxEVT_JOY_BUTTON_UP, ts, wxCtz(deltaUp)+1);
+            SendEvent(wxEVT_JOY_BUTTON_UP, ts, deltaUp);
         if (deltaDown)
-            SendEvent(wxEVT_JOY_BUTTON_DOWN, ts, wxCtz(deltaDown)+1);
+            SendEvent(wxEVT_JOY_BUTTON_DOWN, ts, deltaDown);
 
         if ((m_joyInfo.wXpos != m_lastJoyInfo.wXpos) ||
             (m_joyInfo.wYpos != m_lastJoyInfo.wYpos) ||
diff --git a/src/osx/core/hidjoystick.cpp b/src/osx/core/hidjoystick.cpp
index feace2517e..cf47209311 100644
--- a/src/osx/core/hidjoystick.cpp
+++ b/src/osx/core/hidjoystick.cpp
@@ -872,7 +872,7 @@ void* wxJoystickThread::Entry()
                 wxevent.SetEventType(wxEVT_JOY_BUTTON_UP);
             }
 
-            wxevent.SetButtonChange(nIndex+1);
+            wxevent.SetButtonChange(1 << nIndex);
         }
         else if (nIndex == wxJS_AXIS_X)
         {
diff --git a/src/unix/joystick.cpp b/src/unix/joystick.cpp
index 928e9f6fc9..0e51fd5ca6 100644
--- a/src/unix/joystick.cpp
+++ b/src/unix/joystick.cpp
@@ -181,12 +181,12 @@ void* wxJoystickThread::Entry()
                 if (j_evt.value)
                 {
                     m_buttons |= (1 << j_evt.number);
-                    SendEvent(wxEVT_JOY_BUTTON_DOWN, j_evt.time, j_evt.number);
+                    SendEvent(wxEVT_JOY_BUTTON_DOWN, j_evt.time, 1 << j_evt.number);
                 }
                 else
                 {
                     m_buttons &= ~(1 << j_evt.number);
-                    SendEvent(wxEVT_JOY_BUTTON_UP, j_evt.time, j_evt.number);
+                    SendEvent(wxEVT_JOY_BUTTON_UP, j_evt.time, 1 << j_evt.number);
                 }
             }
         }
diff --git a/tests/misc/misctests.cpp b/tests/misc/misctests.cpp
index b6dd757513..c6f1a0f64b 100644
--- a/tests/misc/misctests.cpp
+++ b/tests/misc/misctests.cpp
@@ -19,6 +19,8 @@
 
 #include "wx/defs.h"
 
+#include "wx/math.h"
+
 // just some classes using wxRTTI for wxStaticCast() test
 #include "wx/tarstrm.h"
 #include "wx/zipstrm.h"
@@ -150,3 +152,12 @@ void MiscTestCase::StaticCast()
 #endif // wxUSE_TARSTREAM
 }
 
+TEST_CASE("wxCTZ", "[math]")
+{
+    CHECK( wxCTZ(1) == 0 );
+    CHECK( wxCTZ(4) == 2 );
+    CHECK( wxCTZ(17) == 0 );
+    CHECK( wxCTZ(0x80000000) == 31 );
+
+    WX_ASSERT_FAILS_WITH_ASSERT( wxCTZ(0) );
+}