diff --git a/submodules/build/iphone-config.site b/submodules/build/iphone-config.site
index b7f89f6a7..e3bd5000c 100644
--- a/submodules/build/iphone-config.site
+++ b/submodules/build/iphone-config.site
@@ -49,3 +49,7 @@ RANLIB="xcrun ranlib"
 
 CPPFLAGS="-Dasm=__asm"
 OBJCFLAGS="-x objective-c -fexceptions -gdwarf-2 -fobjc-abi-version=2 -fobjc-legacy-dispatch"
+#Force install script to use -C so that header files don't get re-written if not changed.
+INSTALL_DATA="ginstall -C"
+
+