diff --git a/configure b/configure
index 2408e3fb6d3..e6ffba53b69 100755
--- a/configure
+++ b/configure
@@ -2570,8 +2570,8 @@ case $_host_os in
 		append_var DEFINES "-DARM"
 		append_var DEFINES "-DNONSTANDARD_PORT"
 		append_var CXXFLAGS "-isystem $DEVKITPRO/libnds/include"
-		append_var CXXFLAGS "-I$DEVKITPRO/portlibs/nds/include"
-		append_var CXXFLAGS "-I$DEVKITPRO/portlibs/armv5te/include"
+		append_var CXXFLAGS "-isystem $DEVKITPRO/portlibs/nds/include"
+		append_var CXXFLAGS "-isystem $DEVKITPRO/portlibs/armv5te/include"
 		append_var CXXFLAGS "-mcpu=arm9tdmi"
 		append_var CXXFLAGS "-mtune=arm9tdmi"
 		append_var CXXFLAGS "-fomit-frame-pointer"