diff --git a/depends/packages/bdb.mk b/depends/packages/bdb.mk
index c8f677490..6b8b8e144 100644
--- a/depends/packages/bdb.mk
+++ b/depends/packages/bdb.mk
@@ -14,7 +14,7 @@ ifneq ($(build_os),darwin)
 $(package)_config_opts_darwin=--disable-atomicsupport
 endif
 $(package)_config_opts_aarch64=--disable-atomicsupport
-$(package)_cxxflags=-std=c++11
+$(package)_cxxflags+=-std=c++11
 endef
 
 define $(package)_preprocess_cmds
diff --git a/depends/packages/boost.mk b/depends/packages/boost.mk
index fde0c92c3..0062c0bdb 100644
--- a/depends/packages/boost.mk
+++ b/depends/packages/boost.mk
@@ -22,7 +22,7 @@ $(package)_archiver_$(host_os)=$($(package)_ar)
 $(package)_toolset_darwin=gcc
 $(package)_archiver_darwin=$($(package)_ar)
 $(package)_config_libraries=chrono,filesystem,program_options,system,thread,test
-$(package)_cxxflags=-std=c++11 -fvisibility=hidden
+$(package)_cxxflags+=-std=c++11 -fvisibility=hidden
 $(package)_cxxflags_linux=-fPIC
 endef