diff --git a/utils/smstools3/Makefile b/utils/smstools3/Makefile
index 062087146..9df7698e7 100644
--- a/utils/smstools3/Makefile
+++ b/utils/smstools3/Makefile
@@ -40,7 +40,7 @@ define Package/smstools3/description
 endef
 
 TARGET_CFLAGS += -D NUMBER_OF_MODEMS=1
-TARGET_CFLAGS += -D USE_ICONV
+TARGET_CFLAGS += $(if $(ICONV_FULL),-D USE_ICONV)
 TARGET_CFLAGS += -D DISABLE_INET_SOCKET
 TARGET_CFLAGS += -W -Wall
 TARGET_CFLAGS += -D_FILE_OFFSET_BITS=64