diff --git a/src/base/pspdev.cmake b/src/base/pspdev.cmake
index de74da76..7e6a82f6 100644
--- a/src/base/pspdev.cmake
+++ b/src/base/pspdev.cmake
@@ -10,7 +10,7 @@ SET(CMAKE_SYSTEM_PROCESSOR mips)
 SET(CMAKE_C_COMPILER psp-gcc)
 SET(CMAKE_CXX_COMPILER psp-g++)
 SET(CMAKE_C_FLAGS_INIT "-isystem ${PSPDEV}/psp/include -I${PSPDEV}/psp/sdk/include -DPSP")
-SET(CMAKE_CXX_FLAGS_INIT "-I${PSPDEV}/psp/include -I${PSPDEV}/psp/sdk/include -DPSP")
+SET(CMAKE_CXX_FLAGS_INIT "-isystem ${PSPDEV}/psp/include -I${PSPDEV}/psp/sdk/include -DPSP")
 SET(CMAKE_EXE_LINKER_FLAGS_INIT "-L${PSPDEV}/lib -L${PSPDEV}/psp/lib -L${PSPDEV}/psp/sdk/lib -Wl,-zmax-page-size=128")
 #SET(CMAKE_SHARED_LINKER_FLAGS_INIT "...")
 #SET(CMAKE_STATIC_LINKER_FLAGS_CONFIG_INIT "...")