diff --git a/Makefile.in b/Makefile.in
index 6ba2457876a..79d0bdd4df2 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -673,6 +673,8 @@ stamps/build-newlib: $(NEWLIB_SRCDIR) $(NEWLIB_SRC_GIT) stamps/build-gcc-newlib-
 		--enable-newlib-io-long-double \
 		--enable-newlib-io-long-long \
 		--enable-newlib-io-c99-formats \
+		--enable-newlib-retargetable-locking \
+		--enable-newlib-reent-check-verify \
 		--enable-newlib-register-fini \
 		CFLAGS_FOR_TARGET="-O2 -D_POSIX_MODE -ffunction-sections -fdata-sections $(CFLAGS_FOR_TARGET)" \
 		CXXFLAGS_FOR_TARGET="-O2 -D_POSIX_MODE -ffunction-sections -fdata-sections $(CXXFLAGS_FOR_TARGET)"
@@ -691,6 +693,8 @@ stamps/build-newlib-nano: $(NEWLIB_SRCDIR) $(NEWLIB_SRC_GIT) stamps/build-gcc-ne
 		$(CONFIGURE_HOST) \
 		--prefix=$(builddir)/install-newlib-nano \
 		--enable-newlib-reent-small \
+		--enable-newlib-retargetable-locking \
+		--enable-newlib-reent-check-verify \
 		--disable-newlib-fvwrite-in-streamio \
 		--disable-newlib-fseek-optimization \
 		--disable-newlib-wide-orient \