diff --git a/core/jni/AndroidRuntime.cpp b/core/jni/AndroidRuntime.cpp
index f7f10c49fbae3..b94ac9c29f9f9 100644
--- a/core/jni/AndroidRuntime.cpp
+++ b/core/jni/AndroidRuntime.cpp
@@ -1052,12 +1052,18 @@ void AndroidRuntime::start(const char* className, const Vector<String8>& options
     if (rootDir == NULL) {
         rootDir = "/system";
         if (!hasDir("/system")) {
-            LOG_FATAL("No root directory specified, and /android does not exist.");
+            LOG_FATAL("No root directory specified, and /system does not exist.");
             return;
         }
         setenv("ANDROID_ROOT", rootDir, 1);
     }
 
+    const char* runtimeRootDir = getenv("ANDROID_RUNTIME_ROOT");
+    if (runtimeRootDir == NULL) {
+        LOG_FATAL("No runtime directory specified with ANDROID_RUNTIME_ROOT environment variable.");
+        return;
+    }
+
     //const char* kernelHack = getenv("LD_ASSUME_KERNEL");
     //ALOGD("Found LD_ASSUME_KERNEL='%s'\n", kernelHack);