diff --git a/contrib/src/gmp/rules.mak b/contrib/src/gmp/rules.mak
index 4309a737bb707c6fc8c0d2a31dbe80ed752997a3..96c7980c7395c0a20e1ef60511d0f7b677111517 100644
--- a/contrib/src/gmp/rules.mak
+++ b/contrib/src/gmp/rules.mak
@@ -14,7 +14,7 @@ gmp: gmp-$(GMP_VERSION).tar.bz2 .sum-gmp
 
 .gmp: gmp
 ifdef HAVE_IOS
-	cd $< && $(HOSTVARS) ./configure --disable-assembly $(HOSTCONF)
+	cd $< && $(HOSTVARS) CFLAGS="$(CFLAGS) -O3" ./configure --disable-assembly $(HOSTCONF)
 else
 	cd $< && $(HOSTVARS) ./configure $(HOSTCONF)
 endif
diff --git a/contrib/src/nettle/rules.mak b/contrib/src/nettle/rules.mak
index e9f526f030dd9ef2a1d0432bc74dd6b8bffdaaa9..b245ccae7f4d9f5e1d6450e9c3790dfd999b227c 100644
--- a/contrib/src/nettle/rules.mak
+++ b/contrib/src/nettle/rules.mak
@@ -22,6 +22,12 @@ nettle: nettle-$(NETTLE_VERSION).tar.gz .sum-nettle
 DEPS_nettle = gmp $(DEPS_gmp)
 
 .nettle: nettle
+ifdef HAVE_IOS
+	cd $< && sed -i.orig s/-ggdb3//g configure.ac
+	cd $< && autoreconf
+	cd $< && $(HOSTVARS) CFLAGS="$(CFLAGS) -O3" ./configure $(HOSTCONF)
+else
 	cd $< && $(HOSTVARS) ./configure $(HOSTCONF)
+endif
 	cd $< && $(MAKE) install
 	touch $@