diff --git a/base-nova/Makefile b/base-nova/Makefile
index 8aa263ef83..54a839efaa 100644
--- a/base-nova/Makefile
+++ b/base-nova/Makefile
@@ -9,7 +9,7 @@ VERBOSE     ?= @
 ECHO        = @echo
 GIT_URL     = https://github.com/alex-ab/NOVA.git
 GIT_REV     = HEAD
-GIT_BRANCH  = r3
+GIT_BRANCH  = r4
 CONTRIB_DIR = contrib
 PATCHES     = $(shell find patches -name '*.patch')
 
diff --git a/base-nova/include/nova/syscall-generic.h b/base-nova/include/nova/syscall-generic.h
index 3de1ae48f6..a50c0d59e9 100644
--- a/base-nova/include/nova/syscall-generic.h
+++ b/base-nova/include/nova/syscall-generic.h
@@ -209,6 +209,7 @@ namespace Nova {
 				STA  = 1 << 18,  /* interruptibility state */
 				TSC  = 1 << 19,  /* time-stamp counter */
 				EFER = 1 << 20,  /* EFER MSR */
+				FPU  = 1 << 31,  /* FPU state */
 
 				IRQ  = EFL | STA | INJ | TSC,
 				ALL  = 0x000fffff & ~CTRL,