diff --git a/arch/um/Makefile b/arch/um/Makefile
index f1d4d67157be0b..ae321282dc6f60 100644
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -68,6 +68,8 @@ KBUILD_CFLAGS += $(CFLAGS) $(CFLAGS-y) -D__arch_um__ \
 	-Din6addr_loopback=kernel_in6addr_loopback \
 	-Din6addr_any=kernel_in6addr_any -Dstrrchr=kernel_strrchr
 
+KBUILD_RUSTFLAGS += -Crelocation-model=pie
+
 KBUILD_AFLAGS += $(ARCH_INCLUDE)
 
 USER_CFLAGS = $(patsubst $(KERNEL_DEFINES),,$(patsubst -I%,,$(KBUILD_CFLAGS))) \
diff --git a/arch/x86/Makefile.um b/arch/x86/Makefile.um
index b3c1ae084180dc..d2e95d1d4db775 100644
--- a/arch/x86/Makefile.um
+++ b/arch/x86/Makefile.um
@@ -1,6 +1,12 @@
 # SPDX-License-Identifier: GPL-2.0
 core-y += arch/x86/crypto/
 
+#
+# Disable SSE and other FP/SIMD instructions to match normal x86
+#
+KBUILD_CFLAGS += -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx
+KBUILD_RUSTFLAGS += -Ctarget-feature=-sse,-sse2,-sse3,-ssse3,-sse4.1,-sse4.2,-avx,-avx2
+
 ifeq ($(CONFIG_X86_32),y)
 START := 0x8048000