diff --git a/include/wx/html/htmldefs.h b/include/wx/html/htmldefs.h
index 26edbeee4b..dc008b77a4 100644
--- a/include/wx/html/htmldefs.h
+++ b/include/wx/html/htmldefs.h
@@ -61,9 +61,9 @@
 #define wxHTML_INDENT_TOP            0x0040
 #define wxHTML_INDENT_BOTTOM         0x0080
 
-#define wxHTML_INDENT_HORIZONTAL     wxHTML_INDENT_LEFT | wxHTML_INDENT_RIGHT
-#define wxHTML_INDENT_VERTICAL       wxHTML_INDENT_TOP | wxHTML_INDENT_BOTTOM
-#define wxHTML_INDENT_ALL            wxHTML_INDENT_VERTICAL | wxHTML_INDENT_HORIZONTAL
+#define wxHTML_INDENT_HORIZONTAL     (wxHTML_INDENT_LEFT | wxHTML_INDENT_RIGHT)
+#define wxHTML_INDENT_VERTICAL       (wxHTML_INDENT_TOP | wxHTML_INDENT_BOTTOM)
+#define wxHTML_INDENT_ALL            (wxHTML_INDENT_VERTICAL | wxHTML_INDENT_HORIZONTAL)