diff --git a/curses.h b/curses.h
index a615ca36..f5ab8c91 100644
--- a/curses.h
+++ b/curses.h
@@ -46,7 +46,7 @@ PDCurses portable platform definitions list:
 # include <wchar.h>
 #endif
 
-#if defined(__cplusplus) || defined(__cplusplus__) || defined(__CPLUSPLUS)
+#ifdef __cplusplus
 extern "C"
 {
 # define bool _bool
@@ -1341,7 +1341,7 @@ PDCEX  int     sb_refresh(void);
 #define PDC_KEY_MODIFIER_ALT     4
 #define PDC_KEY_MODIFIER_NUMLOCK 8
 
-#if defined(__cplusplus) || defined(__cplusplus__) || defined(__CPLUSPLUS)
+#ifdef __cplusplus
 # undef bool
 }
 #endif
diff --git a/panel.h b/panel.h
index 6cfba0fa..36a582c9 100644
--- a/panel.h
+++ b/panel.h
@@ -9,7 +9,7 @@
 
 #include <curses.h>
 
-#if defined(__cplusplus) || defined(__cplusplus__) || defined(__CPLUSPLUS)
+#ifdef __cplusplus
 extern "C"
 {
 #endif
@@ -49,7 +49,7 @@ PDCEX  int     show_panel(PANEL *pan);
 PDCEX  int     top_panel(PANEL *pan);
 PDCEX  void    update_panels(void);
 
-#if defined(__cplusplus) || defined(__cplusplus__) || defined(__CPLUSPLUS)
+#ifdef __cplusplus
 }
 #endif