diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 6ccaef349..d8025b3b4 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -151,6 +151,23 @@ else( WIN32 )
 		include_directories( ${FPU_CONTROL_DIR} )
 		add_definitions( -DHAVE_FPU_CONTROL )
 	endif( FPU_CONTROL_DIR )
+
+	include( CheckCXXSourceCompiles )
+	CHECK_CXX_SOURCE_COMPILES(
+		"#include <stdarg.h>
+		int main() { va_list list1, list2; va_copy(list1, list2); return 0; }"
+		HAS_VA_COPY )
+	if( NOT HAS_VA_COPY )
+		CHECK_CXX_SOURCE_COMPILES(
+			"#include <stdarg.h>
+			int main() { va_list list1, list2; __va_copy(list1, list2); return 0; }"
+			HAS___VA_COPY )
+		if( HAS___VA_COPY )
+			add_definitions( -Dva_copy=__va_copy )
+		else( HAS___VA_COPY )
+			message( SEND_ERROR "Compiler does not support va_copy or __va_copy" )
+		endif( HAS___VA_COPY )
+	endif( NOT HAS_VA_COPY )
 endif( WIN32 )
 
 # Decide on the name of the FMOD library we want to use.