diff --git a/package/gflags/gflags.mk b/package/gflags/gflags.mk
index 9dc4e15b6f..89111ed987 100644
--- a/package/gflags/gflags.mk
+++ b/package/gflags/gflags.mk
@@ -11,7 +11,8 @@ GFLAGS_LICENSE = BSD-3c
 GFLAGS_LICENSE_FILES = COPYING.txt
 
 ifeq ($(BR2_TOOLCHAIN_HAS_THREADS),)
-GFLAGS_CONF_OPTS = -DBUILD_gflags_LIB=OFF -DCMAKE_CXX_FLAGS=-DNO_THREADS
+GFLAGS_CONF_OPTS = -DBUILD_gflags_LIB=OFF \
+	-DCMAKE_CXX_FLAGS="$(TARGET_CXXFLAGS) -DNO_THREADS"
 endif
 
 $(eval $(cmake-package))