diff --git a/build.vc10/daemon.vcxproj b/build.vc10/daemon.vcxproj
index 8d17e8c..a3385e3 100644
--- a/build.vc10/daemon.vcxproj
+++ b/build.vc10/daemon.vcxproj
@@ -119,7 +119,7 @@
       <AdditionalOptions>/Wall /wd4100 /wd4127 /wd4255 /wd4574 /wd4619 /wd4668 /wd4710 /wd4711 /wd4820 %(AdditionalOptions)</AdditionalOptions>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\sys;..\xdr;..\dll;..\libtirpc\tirpc;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>WIN32_LEAN_AND_MEAN;STANDALONE_NFSD;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>WIN32_LEAN_AND_MEAN;STANDALONE_NFSD;NO_CB_4_KRB5P;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <MinimalRebuild>true</MinimalRebuild>
       <ExceptionHandling>
       </ExceptionHandling>
diff --git a/build.vc10/libtirpc.vcxproj b/build.vc10/libtirpc.vcxproj
index 070d42c..6d53ec9 100644
--- a/build.vc10/libtirpc.vcxproj
+++ b/build.vc10/libtirpc.vcxproj
@@ -115,7 +115,7 @@
     <ClCompile>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\libtirpc\tirpc;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>INET6;FD_SETSIZE=128;PORTMAP;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>INET6;FD_SETSIZE=128;PORTMAP;NO_CB_4_KRB5P;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <MinimalRebuild>true</MinimalRebuild>
       <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
       <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
diff --git a/daemon/nfs41_rpc.c b/daemon/nfs41_rpc.c
index 1f39890..ec205b5 100644
--- a/daemon/nfs41_rpc.c
+++ b/daemon/nfs41_rpc.c
@@ -129,6 +129,10 @@ int nfs41_rpc_clnt_create(
         status = GetLastError();
         goto out;
     }
+#ifdef NO_CB_4_KRB5P
+    if (sec_flavor == RPCSEC_AUTHGSS_KRB5P)
+        needcb = 0;
+#endif
     rpc->needcb = needcb;
     rpc->cond = CreateEvent(NULL, TRUE, FALSE, "rpc_recovery_cond");
     if (rpc->cond == NULL) {
diff --git a/daemon/nfs41_session.c b/daemon/nfs41_session.c
index 3e31589..e12307a 100644
--- a/daemon/nfs41_session.c
+++ b/daemon/nfs41_session.c
@@ -279,8 +279,13 @@ int nfs41_session_create(
     }
 
     AcquireSRWLockShared(&client->exid_lock);
+#ifdef NO_CB_4_KRB5P
+    if ((client->roles & (EXCHGID4_FLAG_USE_PNFS_MDS |
+        EXCHGID4_FLAG_USE_NON_PNFS)) && client->rpc->needcb)
+#else
     if (client->roles & (EXCHGID4_FLAG_USE_PNFS_MDS |
         EXCHGID4_FLAG_USE_NON_PNFS))
+#endif
         session->flags |= CREATE_SESSION4_FLAG_CONN_BACK_CHAN;
     ReleaseSRWLockShared(&client->exid_lock);
 
diff --git a/libtirpc/src/clnt_vc.c b/libtirpc/src/clnt_vc.c
index 5849a41..488be66 100644
--- a/libtirpc/src/clnt_vc.c
+++ b/libtirpc/src/clnt_vc.c
@@ -549,19 +549,26 @@ call_again:
 		return(ct->ct_error.re_status);
 	}
 
-    release_fd_lock(ct->ct_fd, mask);
+#ifdef NO_CB_4_KRB5P
+    if (cl->cb_thread != INVALID_HANDLE_VALUE)
+        release_fd_lock(ct->ct_fd, mask);
+#endif
 	/*
 	 * Keep receiving until we get a valid transaction id
 	 */
 
 	while (TRUE) {
-        mutex_lock(&clnt_fd_lock);
-	    while ((vc_fd_locks[WINSOCK_HANDLE_HASH(ct->ct_fd)] && 
-                vc_fd_locks[WINSOCK_HANDLE_HASH(ct->ct_fd)] != GetCurrentThreadId()) || 
-                (ct->reply_msg.rm_xid && ct->reply_msg.rm_xid != x_id))
-		    cond_wait(&vc_cv[WINSOCK_HANDLE_HASH(ct->ct_fd)], &clnt_fd_lock);
-	    vc_fd_locks[WINSOCK_HANDLE_HASH(ct->ct_fd)] = GetCurrentThreadId();
-	    mutex_unlock(&clnt_fd_lock);
+#ifdef NO_CB_4_KRB5P
+        if (cl->cb_thread != INVALID_HANDLE_VALUE) {
+            mutex_lock(&clnt_fd_lock);
+	        while ((vc_fd_locks[WINSOCK_HANDLE_HASH(ct->ct_fd)] && 
+                    vc_fd_locks[WINSOCK_HANDLE_HASH(ct->ct_fd)] != GetCurrentThreadId()) || 
+                    (ct->reply_msg.rm_xid && ct->reply_msg.rm_xid != x_id))
+		        cond_wait(&vc_cv[WINSOCK_HANDLE_HASH(ct->ct_fd)], &clnt_fd_lock);
+	        vc_fd_locks[WINSOCK_HANDLE_HASH(ct->ct_fd)] = GetCurrentThreadId();
+	        mutex_unlock(&clnt_fd_lock);
+        }
+#endif
 
         xdrs->x_op = XDR_DECODE;
 		ct->reply_msg.acpted_rply.ar_verf = _null_auth;