diff --git a/ci/test/00_setup_env_native_fuzz_with_msan.sh b/ci/test/00_setup_env_native_fuzz_with_msan.sh
index d35701160af..7886f6efc97 100755
--- a/ci/test/00_setup_env_native_fuzz_with_msan.sh
+++ b/ci/test/00_setup_env_native_fuzz_with_msan.sh
@@ -15,7 +15,7 @@ export MSAN_AND_LIBCXX_FLAGS="${MSAN_FLAGS} ${LIBCXX_FLAGS}"
 export CONTAINER_NAME="ci_native_fuzz_msan"
 export PACKAGES="clang-12 llvm-12 cmake"
 # BDB generates false-positives and will be removed in future
-export DEP_OPTS="NO_BDB=1 NO_QT=1 CC='clang' CXX='clang++' CFLAGS='${MSAN_FLAGS}' CXXFLAGS='${MSAN_AND_LIBCXX_FLAGS}' libevent_cflags='${MSAN_FLAGS}' sqlite_cflags='${MSAN_FLAGS}' zeromq_cxxflags='-std=c++17 ${MSAN_AND_LIBCXX_FLAGS}'"
+export DEP_OPTS="NO_BDB=1 NO_QT=1 CC='clang' CXX='clang++' CFLAGS='${MSAN_FLAGS}' CXXFLAGS='${MSAN_AND_LIBCXX_FLAGS}'"
 export GOAL="install"
 export BITCOIN_CONFIG="--enable-fuzz --with-sanitizers=fuzzer,memory --disable-hardening --with-asm=no CC=clang CXX=clang++ CFLAGS='${MSAN_FLAGS}' CXXFLAGS='${MSAN_AND_LIBCXX_FLAGS}'"
 export USE_MEMORY_SANITIZER="true"
diff --git a/ci/test/00_setup_env_native_msan.sh b/ci/test/00_setup_env_native_msan.sh
index 48049a0a3c7..1f9209bafb0 100755
--- a/ci/test/00_setup_env_native_msan.sh
+++ b/ci/test/00_setup_env_native_msan.sh
@@ -15,7 +15,7 @@ export MSAN_AND_LIBCXX_FLAGS="${MSAN_FLAGS} ${LIBCXX_FLAGS}"
 export CONTAINER_NAME="ci_native_msan"
 export PACKAGES="clang-12 llvm-12 cmake"
 # BDB generates false-positives and will be removed in future
-export DEP_OPTS="NO_BDB=1 NO_QT=1 CC='clang' CXX='clang++' CFLAGS='${MSAN_FLAGS}' CXXFLAGS='${MSAN_AND_LIBCXX_FLAGS}' libevent_cflags='${MSAN_FLAGS}' sqlite_cflags='${MSAN_FLAGS}' zeromq_cxxflags='-std=c++17 ${MSAN_AND_LIBCXX_FLAGS}'"
+export DEP_OPTS="NO_BDB=1 NO_QT=1 CC='clang' CXX='clang++' CFLAGS='${MSAN_FLAGS}' CXXFLAGS='${MSAN_AND_LIBCXX_FLAGS}'"
 export GOAL="install"
 export BITCOIN_CONFIG="--with-sanitizers=memory --disable-hardening --with-asm=no CC=clang CXX=clang++ CFLAGS='${MSAN_FLAGS}' CXXFLAGS='${MSAN_AND_LIBCXX_FLAGS}'"
 export USE_MEMORY_SANITIZER="true"
diff --git a/depends/hosts/default.mk b/depends/hosts/default.mk
index 7c76331ab4a..bad4568bcb1 100644
--- a/depends/hosts/default.mk
+++ b/depends/hosts/default.mk
@@ -28,8 +28,13 @@ host_$1=$$($(host_arch)_$(host_os)_$1)
 endef
 
 define add_host_flags_func
+ifeq ($(filter $(origin $1),undefined default),)
+$(host_arch)_$(host_os)_$1 =
+$(host_arch)_$(host_os)_$(release_type)_$1 = $($1)
+else
 $(host_arch)_$(host_os)_$1 += $($(host_os)_$1)
 $(host_arch)_$(host_os)_$(release_type)_$1 += $($(host_os)_$(release_type)_$1)
+endif
 host_$1 = $$($(host_arch)_$(host_os)_$1)
 host_$(release_type)_$1 = $$($(host_arch)_$(host_os)_$(release_type)_$1)
 endef