diff --git a/GNUmakefile b/GNUmakefile
index e4c9a07..199fac1 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -23,8 +23,8 @@ OBJDIR	:= obj$(OBJSUFFIX)
 
 TOP	:= $(shell echo $${PWD-`pwd`})
 GTEST_DIR ?= $(TOP)/gtest
-ZOOKEEPER_LIB := /usr/local/lib/libzookeeper_mt.a
-ZOOKEEPER_DIR := /usr/local/zookeeper-3.4.5
+ZOOKEEPER_LIB ?= /usr/local/lib/libzookeeper_mt.a
+ZOOKEEPER_DIR ?= /usr/local/zookeeper-3.4.5
 
 ifeq ($(DEBUG),yes)
 BASECFLAGS := -g
diff --git a/src/MasterService.cc b/src/MasterService.cc
index 93cfb5d..02876c7 100644
--- a/src/MasterService.cc
+++ b/src/MasterService.cc
@@ -613,7 +613,7 @@ MasterService::multiWrite(const WireFormat::MultiOp::Request* reqHdr,
             reqOffset, currentReq->valueLength);
         reqOffset += currentReq->valueLength;
 
-        if (stringKey == NULL || value == NULL) {
+        if (stringKey == NULL) {
             respHdr->common.status = STATUS_REQUEST_FORMAT_ERROR;
             break;
         }