diff --git a/SConstruct b/SConstruct
index 5a533556c..688962a4d 100644
--- a/SConstruct
+++ b/SConstruct
@@ -1157,6 +1157,7 @@ gcc-4.8.
 		if Compile(context, text=include, main=_main, msg='whether compiler implements __builtin_bswap{16,32,64} functions', successflags=_successflags_bswap16) or \
 			Compile(context, text=include, main=_main, msg='whether compiler implements __builtin_bswap{32,64} functions', successflags=_successflags_bswap):
 			return
+	implicit_tests.append(_implicit_test.RecordedTest('check_optimize_builtin_constant_p', "assume compiler optimizes __builtin_constant_p"))
 	@_custom_test
 	def check_builtin_constant_p(self,context):
 		"""
@@ -1184,7 +1185,7 @@ static int a(int b){
 '''
 		main = 'return a(1) + a(2)'
 		Define = context.sconf.Define
-		if self.Link(context, text=f % 'c(b)', main=main, msg='whether compiler optimizes __builtin_constant_p'):
+		if self.Link(context, text=f % 'c(b)', main=main, msg='whether compiler optimizes __builtin_constant_p', calling_function='optimize_builtin_constant_p'):
 			Define('DXX_HAVE_BUILTIN_CONSTANT_P')
 			Define('DXX_CONSTANT_TRUE(E)', '(__builtin_constant_p((E)) && (E))')
 			dxx_builtin_constant_p = '__builtin_constant_p(A)'
diff --git a/common/include/fwd-gr.h b/common/include/fwd-gr.h
index 49631964e..978b20b76 100644
--- a/common/include/fwd-gr.h
+++ b/common/include/fwd-gr.h
@@ -306,7 +306,7 @@ static inline void _gr_set_current_canvas_inline(grs_canvas *canv)
 static inline void gr_set_current_canvas(grs_canvas *canv)
 {
 #ifdef DXX_HAVE_BUILTIN_CONSTANT_P
-	if (__builtin_constant_p(!canv))
+	if (dxx_builtin_constant_p(!canv))
 		_gr_set_current_canvas_inline(canv);
 	else
 #endif
diff --git a/common/main/multi.h b/common/main/multi.h
index 9afe07242..4d0d248d3 100644
--- a/common/main/multi.h
+++ b/common/main/multi.h
@@ -506,7 +506,7 @@ void multi_send_endlevel_start();
 static inline void multi_send_endlevel_start(bool secret)
 {
 #ifdef DXX_HAVE_BUILTIN_CONSTANT_P
-	if (!__builtin_constant_p(secret) || secret)
+	if (!dxx_builtin_constant_p(!!secret) || secret)
 		DXX_ALWAYS_ERROR_FUNCTION(multi_send_endlevel_start_with_secret, "secret not supported in Descent II");
 #endif
 	(void)secret;