diff --git a/include/make/options.mk b/include/make/options.mk
index f439be345..9e96f875c 100644
--- a/include/make/options.mk
+++ b/include/make/options.mk
@@ -37,3 +37,16 @@ reset_opt_vars = $(foreach name,INC LIB CFLAGS LDFLAGS SRC,$(eval $(1)_$(name)=)
 
 # preset all variables for all supported build options among use_opts
 reset_opts_vars = $(foreach opt,$(patsubst USE_%,%,$(use_opts)) SSL WOLFSSL,$(call reset_opt_vars,$(opt)))
+
+# append $(1)_{C,LD}FLAGS into OPTIONS_{C,LD}FLAGS if not empty
+define collect_opt_flags =
+  ifneq ($$($(1)_CFLAGS),)
+    OPTIONS_CFLAGS += $$($(1)_CFLAGS)
+  endif
+  ifneq ($$($(1)_LDFLAGS),)
+    OPTIONS_LDFLAGS += $$($(1)_LDFLAGS)
+  endif
+endef
+
+# collect all known USE_foo's foo_{C,LD}FLAGS into OPTIONS_{C,LD}FLAGS
+collect_opts_flags = $(foreach opt,$(patsubst USE_%,%,$(use_opts)) SSL,$(eval $(call collect_opt_flags,$(opt))))