diff --git a/.travis.yml b/.travis.yml
index 22bd322..2f73dce 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,7 +8,7 @@ matrix:
       cache: apt
       before_install:
         - sudo apt-get update -qq
-        - sudo apt-get install -qq cppcheck libfuse-dev openjdk-7-jdk libjsoncpp-dev
+        - sudo apt-get install -qq cppcheck libfuse-dev openjdk-7-jdk
         - sudo update-alternatives --set java /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java
       script:
         - ./autogen.sh
@@ -24,7 +24,7 @@ matrix:
       osx_image: xcode8.3
       before_install:
         - brew update
-        - brew install truncate jsoncpp
+        - brew install truncate
         - brew tap caskroom/cask
         - brew cask install osxfuse
         - if [ -f /Library/Filesystems/osxfusefs.fs/Support/load_osxfusefs ]; then sudo chmod +s /Library/Filesystems/osxfusefs.fs/Support/load_osxfusefs ; elif [ -f /Library/Filesystems/osxfuse.fs/Contents/Resources/load_osxfuse ]; then sudo chmod +s /Library/Filesystems/osxfuse.fs/Contents/Resources/load_osxfuse ; fi
diff --git a/configure.ac b/configure.ac
index a4db042..5adb891 100644
--- a/configure.ac
+++ b/configure.ac
@@ -176,13 +176,13 @@ dnl
 dnl For PKG_CONFIG before checking nss/gnutls.
 dnl this is redundant checking, but we need checking before following.
 dnl
-PKG_CHECK_MODULES([common_lib_checking], [fuse >= ${min_fuse_version} libcurl >= 7.0 libxml-2.0 >= 2.6 jsoncpp >= 0.6 ])
+PKG_CHECK_MODULES([common_lib_checking], [fuse >= ${min_fuse_version} libcurl >= 7.0 libxml-2.0 >= 2.6 ])
 
 AC_MSG_CHECKING([compile s3fs with])
 case "${auth_lib}" in
 openssl)
   AC_MSG_RESULT(OpenSSL)
-  PKG_CHECK_MODULES([DEPS], [fuse >= ${min_fuse_version} libcurl >= 7.0 libxml-2.0 >= 2.6 libcrypto >= 0.9 jsoncpp >= 0.6 ])
+  PKG_CHECK_MODULES([DEPS], [fuse >= ${min_fuse_version} libcurl >= 7.0 libxml-2.0 >= 2.6 libcrypto >= 0.9 ])
   ;;
 gnutls)
   AC_MSG_RESULT(GnuTLS-gcrypt)
@@ -191,7 +191,7 @@ gnutls)
   AS_IF([test "$gnutls_nettle" = ""], [AC_CHECK_LIB(gcrypt, gcry_control, [gnutls_nettle=0])])
   AS_IF([test $gnutls_nettle = 0],
     [
-      PKG_CHECK_MODULES([DEPS], [fuse >= ${min_fuse_version} libcurl >= 7.0 libxml-2.0 >= 2.6 gnutls >= 2.12.0 jsoncpp >= 0.6 ])
+      PKG_CHECK_MODULES([DEPS], [fuse >= ${min_fuse_version} libcurl >= 7.0 libxml-2.0 >= 2.6 gnutls >= 2.12.0 ])
       LIBS="-lgnutls -lgcrypt $LIBS"
       AC_MSG_CHECKING([gnutls is build with])
       AC_MSG_RESULT(gcrypt)
@@ -205,7 +205,7 @@ nettle)
   AS_IF([test "$gnutls_nettle" = ""], [AC_CHECK_LIB(nettle, nettle_MD5Init, [gnutls_nettle=1])])
   AS_IF([test $gnutls_nettle = 1],
     [
-      PKG_CHECK_MODULES([DEPS], [fuse >= ${min_fuse_version} libcurl >= 7.0 libxml-2.0 >= 2.6 nettle >= 2.7.1 jsoncpp >= 0.6 ])
+      PKG_CHECK_MODULES([DEPS], [fuse >= ${min_fuse_version} libcurl >= 7.0 libxml-2.0 >= 2.6 nettle >= 2.7.1 ])
       LIBS="-lgnutls -lnettle $LIBS"
       AC_MSG_CHECKING([gnutls is build with])
       AC_MSG_RESULT(nettle)
@@ -214,7 +214,7 @@ nettle)
   ;;
 nss)
   AC_MSG_RESULT(NSS)
-  PKG_CHECK_MODULES([DEPS], [fuse >= ${min_fuse_version} libcurl >= 7.0 libxml-2.0 >= 2.6 nss >= 3.15.0 jsoncpp >= 0.6 ])
+  PKG_CHECK_MODULES([DEPS], [fuse >= ${min_fuse_version} libcurl >= 7.0 libxml-2.0 >= 2.6 nss >= 3.15.0 ])
   ;;
 *)
   AC_MSG_ERROR([unknown ssl library type.])
diff --git a/src/curl.cpp b/src/curl.cpp
index d623403..f550e7f 100644
--- a/src/curl.cpp
+++ b/src/curl.cpp
@@ -42,8 +42,6 @@
 #include <algorithm>
 #include <list>
 #include <vector>
-#include <json/json.h>
-#include <json/reader.h>
 
 #include "common.h"
 #include "curl.h"
@@ -1426,23 +1424,39 @@ bool S3fsCurl::ParseIAMCredentialResponse(const char* response, iamcredmap_t& ke
   if(!response){
     return false;
   }
-
-  Json::Value root;
-  Json::Reader reader;
-
-  if (!reader.parse(response, root)) {
-    return false;
+  istringstream sscred(response);
+  string        oneline;
+  keyval.clear();
+  while(getline(sscred, oneline, '\n')){
+    string::size_type pos;
+    string            key;
+    string            val;
+    if(string::npos != (pos = oneline.find(IAMCRED_ACCESSKEYID))){
+      key = IAMCRED_ACCESSKEYID;
+    }else if(string::npos != (pos = oneline.find(IAMCRED_SECRETACCESSKEY))){
+      key = IAMCRED_SECRETACCESSKEY;
+    }else if(string::npos != (pos = oneline.find(IAMCRED_ACCESSTOKEN))){
+      key = IAMCRED_ACCESSTOKEN;
+    }else if(string::npos != (pos = oneline.find(IAMCRED_EXPIRATION))){
+      key = IAMCRED_EXPIRATION;
+    }else if(string::npos != (pos = oneline.find(IAMCRED_ROLEARN))){
+      key = IAMCRED_ROLEARN;
+    }else{
+      continue;
+    }
+    if(string::npos == (pos = oneline.find(':', pos + key.length()))){
+      continue;
+    }
+    if(string::npos == (pos = oneline.find('\"', pos))){
+      continue;
+    }
+    oneline = oneline.substr(pos + sizeof(char));
+    if(string::npos == (pos = oneline.find('\"'))){
+      continue;
+    }
+    val = oneline.substr(0, pos);
+    keyval[key] = val;
   }
-
-  keyval[string(IAMCRED_ACCESSKEYID)] = root.get(IAMCRED_ACCESSKEYID, "").asString();
-  keyval[string(IAMCRED_SECRETACCESSKEY)] = root.get(IAMCRED_SECRETACCESSKEY, "").asString();
-  keyval[string(IAMCRED_ACCESSTOKEN)] = root.get(IAMCRED_ACCESSTOKEN, "").asString();
-  keyval[string(IAMCRED_EXPIRATION)] = root.get(IAMCRED_EXPIRATION, "").asString();
-
-  if (S3fsCurl::is_ecs) {
-    keyval[string(IAMCRED_ROLEARN)] = root.get(IAMCRED_ROLEARN, "").asString();
-  }
-
   return true;
 }