diff --git a/package/swconfig/Makefile b/package/swconfig/Makefile
index bec94a1ca0980ffe28f74a91ff4e40e215fe7ec1..a7bed73174d768f50bf25cfb158fcedb96d9a5cd 100644
--- a/package/swconfig/Makefile
+++ b/package/swconfig/Makefile
@@ -21,6 +21,7 @@ define Package/swconfig
 endef
 
 TARGET_CPPFLAGS := \
+	-D_GNU_SOURCE \
 	-I$(STAGING_DIR)/usr/include/libnl-tiny \
 	-I$(LINUX_DIR)/include \
 	-I$(PKG_BUILD_DIR) \
diff --git a/package/wprobe/Makefile b/package/wprobe/Makefile
index 02e9919aa2250755dd61fa0a7c3b9f6fc67f0ea6..536a85eb2a7294424a901e4d6dd927cb295b7813 100644
--- a/package/wprobe/Makefile
+++ b/package/wprobe/Makefile
@@ -61,6 +61,7 @@ define Build/Prepare
 endef
 
 TARGET_CPPFLAGS := \
+	-D_GNU_SOURCE \
 	-I$(STAGING_DIR)/usr/include/libnl-tiny \
 	$(TARGET_CPPFLAGS)