diff --git a/library/Makefile b/library/Makefile
index 7d25343..00528b3 100644
--- a/library/Makefile
+++ b/library/Makefile
@@ -90,9 +90,9 @@
 # tls
 libmbedtls.a: $(OBJS_TLS)
 	echo "  AR    $@"
-	$(AR) rc $@ $(OBJS_TLS)
+	$(AR) -rc $@ $(OBJS_TLS)
 	echo "  RL    $@"
-	$(AR) s $@
+	$(AR) -s $@
 
 libmbedtls.$(SOEXT_TLS): $(OBJS_TLS) libmbedx509.so
 	echo "  LD    $@"
@@ -113,9 +113,9 @@
 # x509
 libmbedx509.a: $(OBJS_X509)
 	echo "  AR    $@"
-	$(AR) rc $@ $(OBJS_X509)
+	$(AR) -rc $@ $(OBJS_X509)
 	echo "  RL    $@"
-	$(AR) s $@
+	$(AR) -s $@
 
 libmbedx509.$(SOEXT_X509): $(OBJS_X509) libmbedcrypto.so
 	echo "  LD    $@"
@@ -136,9 +136,9 @@
 # crypto
 libmbedcrypto.a: $(OBJS_CRYPTO)
 	echo "  AR    $@"
-	$(AR) rc $@ $(OBJS_CRYPTO)
+	$(AR) -rc $@ $(OBJS_CRYPTO)
 	echo "  RL    $@"
-	$(AR) s $@
+	$(AR) -s $@
 
 libmbedcrypto.$(SOEXT_CRYPTO): $(OBJS_CRYPTO)
 	echo "  LD    $@"