diff --git a/libs/binder/tests/binderRpcTest.cpp b/libs/binder/tests/binderRpcTest.cpp
index 287e077..d6aa6c6 100644
--- a/libs/binder/tests/binderRpcTest.cpp
+++ b/libs/binder/tests/binderRpcTest.cpp
@@ -1120,7 +1120,7 @@
                                            ::testing::Values(true), ::testing::Values(true)),
                         BinderRpc::PrintParamInfo);
 #else // BINDER_RPC_TO_TRUSTY_TEST
-static bool testSupportVsockLoopback() {
+bool testSupportVsockLoopback() {
     // We don't need to enable TLS to know if vsock is supported.
     unsigned int vsockPort = allocateVsockPort();
 
@@ -1220,7 +1220,15 @@
 
     if (hasPreconnected) ret.push_back(SocketType::PRECONNECTED);
 
+#ifdef __BIONIC__
+    // Devices may not have vsock support. AVF tests will verify whether they do, but
+    // we can't require it due to old kernels for the time being.
     static bool hasVsockLoopback = testSupportVsockLoopback();
+#else
+    // On host machines, we always assume we have vsock loopback. If we don't, the
+    // subsequent failures will be more clear than showing one now.
+    static bool hasVsockLoopback = true;
+#endif
 
     if (hasVsockLoopback) {
         ret.push_back(SocketType::VSOCK);
diff --git a/libs/binder/tests/binderRpcTestService.cpp b/libs/binder/tests/binderRpcTestService.cpp
index a9736d5..66221c5 100644
--- a/libs/binder/tests/binderRpcTestService.cpp
+++ b/libs/binder/tests/binderRpcTestService.cpp
@@ -139,7 +139,8 @@
             CHECK_EQ(OK, server->setupRawSocketServer(std::move(socketFd)));
             break;
         case SocketType::VSOCK:
-            CHECK_EQ(OK, server->setupVsockServer(VMADDR_CID_LOCAL, serverConfig.vsockPort));
+            CHECK_EQ(OK, server->setupVsockServer(VMADDR_CID_LOCAL, serverConfig.vsockPort))
+                    << "Need `sudo modprobe vsock_loopback`?";
             break;
         case SocketType::INET: {
             CHECK_EQ(OK, server->setupInetServer(kLocalInetAddress, 0, &outPort));