diff -up wxGTK-2.8.12/src/gtk/bdiag.xbm.char wxGTK-2.8.12/src/gtk/bdiag.xbm
--- wxGTK-2.8.12/src/gtk/bdiag.xbm.char	2011-03-22 13:19:01.000000000 +0100
+++ wxGTK-2.8.12/src/gtk/bdiag.xbm	2016-02-20 10:38:50.000000000 +0100
@@ -1,6 +1,6 @@
 #define bdiag_width 16
 #define bdiag_height 16
-static char bdiag_bits[] = {
+static unsigned char bdiag_bits[] = {
    0x80, 0x80, 0x40, 0x40, 0x20, 0x20, 0x10, 0x10, 0x08, 0x08, 0x04, 0x04,
    0x02, 0x02, 0x01, 0x01, 0x80, 0x80, 0x40, 0x40, 0x20, 0x20, 0x10, 0x10,
    0x08, 0x08, 0x04, 0x04, 0x02, 0x02, 0x01, 0x01};
diff -up wxGTK-2.8.12/src/gtk/cdiag.xbm.char wxGTK-2.8.12/src/gtk/cdiag.xbm
--- wxGTK-2.8.12/src/gtk/cdiag.xbm.char	2011-03-22 13:19:01.000000000 +0100
+++ wxGTK-2.8.12/src/gtk/cdiag.xbm	2016-02-20 10:38:50.000000000 +0100
@@ -1,6 +1,6 @@
 #define cdiag_width 16
 #define cdiag_height 16
-static char cdiag_bits[] = {
+static unsigned char cdiag_bits[] = {
    0x81, 0x81, 0x42, 0x42, 0x24, 0x24, 0x18, 0x18, 0x18, 0x18, 0x24, 0x24,
    0x42, 0x42, 0x81, 0x81, 0x81, 0x81, 0x42, 0x42, 0x24, 0x24, 0x18, 0x18,
    0x18, 0x18, 0x24, 0x24, 0x42, 0x42, 0x81, 0x81};
diff -up wxGTK-2.8.12/src/gtk/cross.xbm.char wxGTK-2.8.12/src/gtk/cross.xbm
--- wxGTK-2.8.12/src/gtk/cross.xbm.char	2011-03-22 13:19:01.000000000 +0100
+++ wxGTK-2.8.12/src/gtk/cross.xbm	2016-02-20 10:38:50.000000000 +0100
@@ -1,6 +1,6 @@
 #define cross_width 15
 #define cross_height 15
-static char cross_bits[] = {
+static unsigned char cross_bits[] = {
    0x84, 0x10, 0x84, 0x10, 0xff, 0x7f, 0x84, 0x10, 0x84, 0x10, 0x84, 0x10,
    0x84, 0x10, 0xff, 0x7f, 0x84, 0x10, 0x84, 0x10, 0x84, 0x10, 0x84, 0x10,
    0xff, 0x7f, 0x84, 0x10, 0x84, 0x10};
diff -up wxGTK-2.8.12/src/gtk/dcclient.cpp.char wxGTK-2.8.12/src/gtk/dcclient.cpp
--- wxGTK-2.8.12/src/gtk/dcclient.cpp.char	2016-02-20 10:38:50.000000000 +0100
+++ wxGTK-2.8.12/src/gtk/dcclient.cpp	2016-02-20 10:49:11.000000000 +0100
@@ -427,13 +427,24 @@ void wxWindowDC::SetUpDC()
 
     if (!hatch_bitmap)
     {
+#define CREATE_FROM_XBM_DATA(name) \
+        gdk_bitmap_create_from_data \
+        ( \
+            NULL, \
+            reinterpret_cast<gchar *>(name ## _bits), \
+            name ## _width, \
+            name ## _height \
+        )
+
         hatch_bitmap    = hatches;
-        hatch_bitmap[0] = gdk_bitmap_create_from_data( (GdkWindow *) NULL, bdiag_bits, bdiag_width, bdiag_height );
-        hatch_bitmap[1] = gdk_bitmap_create_from_data( (GdkWindow *) NULL, cdiag_bits, cdiag_width, cdiag_height );
-        hatch_bitmap[2] = gdk_bitmap_create_from_data( (GdkWindow *) NULL, fdiag_bits, fdiag_width, fdiag_height );
-        hatch_bitmap[3] = gdk_bitmap_create_from_data( (GdkWindow *) NULL, cross_bits, cross_width, cross_height );
-        hatch_bitmap[4] = gdk_bitmap_create_from_data( (GdkWindow *) NULL, horiz_bits, horiz_width, horiz_height );
-        hatch_bitmap[5] = gdk_bitmap_create_from_data( (GdkWindow *) NULL, verti_bits, verti_width, verti_height );
+        hatch_bitmap[0] = CREATE_FROM_XBM_DATA(bdiag);
+        hatch_bitmap[1] = CREATE_FROM_XBM_DATA(cdiag);
+        hatch_bitmap[2] = CREATE_FROM_XBM_DATA(fdiag);
+        hatch_bitmap[3] = CREATE_FROM_XBM_DATA(cross);
+        hatch_bitmap[4] = CREATE_FROM_XBM_DATA(horiz);
+        hatch_bitmap[5] = CREATE_FROM_XBM_DATA(verti);
+
+#undef CREATE_FROM_XBM_DATA
     }
 }
 
diff -up wxGTK-2.8.12/src/gtk/fdiag.xbm.char wxGTK-2.8.12/src/gtk/fdiag.xbm
--- wxGTK-2.8.12/src/gtk/fdiag.xbm.char	2011-03-22 13:19:01.000000000 +0100
+++ wxGTK-2.8.12/src/gtk/fdiag.xbm	2016-02-20 10:38:50.000000000 +0100
@@ -1,6 +1,6 @@
 #define fdiag_width 16
 #define fdiag_height 16
-static char fdiag_bits[] = {
+static unsigned char fdiag_bits[] = {
    0x01, 0x01, 0x02, 0x02, 0x04, 0x04, 0x08, 0x08, 0x10, 0x10, 0x20, 0x20,
    0x40, 0x40, 0x80, 0x80, 0x01, 0x01, 0x02, 0x02, 0x04, 0x04, 0x08, 0x08,
    0x10, 0x10, 0x20, 0x20, 0x40, 0x40, 0x80, 0x80};
diff -up wxGTK-2.8.12/src/gtk/horiz.xbm.char wxGTK-2.8.12/src/gtk/horiz.xbm
--- wxGTK-2.8.12/src/gtk/horiz.xbm.char	2011-03-22 13:19:01.000000000 +0100
+++ wxGTK-2.8.12/src/gtk/horiz.xbm	2016-02-20 10:38:50.000000000 +0100
@@ -1,6 +1,6 @@
 #define horiz_width 15
 #define horiz_height 15
-static char horiz_bits[] = {
+static unsigned char horiz_bits[] = {
    0x00, 0x00, 0x00, 0x00, 0xff, 0x7f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0xff, 0x7f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0xff, 0x7f, 0x00, 0x00, 0x00, 0x00};
diff -up wxGTK-2.8.12/src/gtk/verti.xbm.char wxGTK-2.8.12/src/gtk/verti.xbm
--- wxGTK-2.8.12/src/gtk/verti.xbm.char	2011-03-22 13:19:02.000000000 +0100
+++ wxGTK-2.8.12/src/gtk/verti.xbm	2016-02-20 10:38:50.000000000 +0100
@@ -1,6 +1,6 @@
 #define verti_width 15
 #define verti_height 15
-static char verti_bits[] = {
+static unsigned char verti_bits[] = {
    0x84, 0x10, 0x84, 0x10, 0x84, 0x10, 0x84, 0x10, 0x84, 0x10, 0x84, 0x10,
    0x84, 0x10, 0x84, 0x10, 0x84, 0x10, 0x84, 0x10, 0x84, 0x10, 0x84, 0x10,
    0x84, 0x10, 0x84, 0x10, 0x84, 0x10};