diff --git a/mk/prefix.mk b/mk/prefix.mk
index 6df2771..02ce5a4 100644
--- a/mk/prefix.mk
+++ b/mk/prefix.mk
@@ -75,7 +75,6 @@ $(PREFIX)/binutils-install: $(PREFIX)/binutils
 	rm -rf "$<-build" "$@.partial" "$@"
 	mkdir -p "$<-build" "$@.partial"
 	cd "$<-build" && \
-	export CFLAGS="-march=x86-64" CXXFLAGS="-march=x86-64" && \
 	"$(ROOT)/$</configure" \
 		--target="$(TARGET)" \
 		--program-prefix="$(TARGET)-" \
@@ -107,7 +106,6 @@ $(PREFIX)/gcc-freestanding-install: $(PREFIX)/gcc | $(PREFIX)/binutils-install
 	cp -r "$(PREFIX)/binutils-install" "$@.partial"
 	cd "$<-freestanding-build" && \
 	export PATH="$(ROOT)/$@.partial/bin:$$PATH" && \
-	export CFLAGS="-march=x86-64" CXXFLAGS="-march=x86-64" && \
 	"$(ROOT)/$</configure" \
 		--target="$(TARGET)" \
 		--program-prefix="$(TARGET)-" \
@@ -129,7 +127,6 @@ $(PREFIX)/rust-freestanding-install: $(ROOT)/rust | $(PREFIX)/binutils-install
 	cp -r "$(PREFIX)/binutils-install" "$@.partial"
 	cd "$(PREFIX)/rust-freestanding-build" && \
 	export PATH="$(ROOT)/$@.partial/bin:$$PATH" && \
-	export CFLAGS="-march=x86-64" CXXFLAGS="-march=x86-64" && \
 	"$</configure" \
 		--prefix="/" \
 		--disable-docs \
@@ -165,7 +162,6 @@ $(PREFIX)/gcc-install: $(PREFIX)/gcc | $(PREFIX)/relibc-freestanding-install
 	cp -r "$(PREFIX_BASE_INSTALL)" "$@.partial"
 	cd "$<-build" && \
 	export PATH="$(ROOT)/$@.partial/bin:$$PATH" && \
-	export CFLAGS="-march=x86-64" CXXFLAGS="-march=x86-64" && \
 	"$(ROOT)/$</configure" \
 		--target="$(TARGET)" \
 		--program-prefix="$(TARGET)-" \
@@ -203,7 +199,6 @@ $(PREFIX)/rust-install: $(ROOT)/rust | $(PREFIX)/gcc-install $(PREFIX)/relibc-fr
 	cp -r "$(PREFIX)/relibc-freestanding-install/$(TARGET)" "$@.partial"
 	cd "$(PREFIX)/rust-build" && \
 	export PATH="$(ROOT)/$@.partial/bin:$$PATH" && \
-	export CFLAGS="-march=x86-64" CXXFLAGS="-march=x86-64" && \
 	"$</configure" \
 		--prefix="/" \
 		--disable-docs \