diff --git a/adb/commandline.cpp b/adb/commandline.cpp
index 8575c86..bc58c91 100644
--- a/adb/commandline.cpp
+++ b/adb/commandline.cpp
@@ -204,7 +204,10 @@
         "  adb version                  - show version num\n"
         "\n"
         "scripting:\n"
-        "  adb wait-for-device          - block until device is online\n"
+        "  adb wait-for[-<transport>]-<state>\n"
+        "                               - wait for device to be in the given state:\n"
+        "                                 device, recovery, sideload, or bootloader\n"
+        "                                 Transport is: usb, local or any [default=any]\n"
         "  adb start-server             - ensure that there is a server running\n"
         "  adb kill-server              - kill the server if it is running\n"
         "  adb get-state                - prints: offline | bootloader | device\n"
@@ -1010,19 +1013,49 @@
 #endif /* !defined(_WIN32) */
 }
 
+static bool check_wait_for_device_syntax(const char* service) {
+    // TODO: when we have libc++ for Windows, use a regular expression instead.
+    // wait-for-((any|local|usb)-)?(bootloader|device|recovery|sideload)
+
+    char type[20];
+    char state[20];
+    int length = 0;
+    if (sscanf(service, "wait-for-%20[a-z]-%20[a-z]%n", type, state, &length) < 2 ||
+        length != static_cast<int>(strlen(service))) {
+        fprintf(stderr, "adb: couldn't parse 'wait-for' command: %s\n", service);
+        return false;
+    }
+
+    if (strcmp(type, "any") != 0 && strcmp(type, "local") != 0 && strcmp(type, "usb") != 0) {
+        fprintf(stderr, "adb: unknown type %s; expected 'any', 'local', or 'usb'\n", type);
+        return false;
+    }
+    if (strcmp(state, "bootloader") != 0 && strcmp(state, "device") != 0 &&
+        strcmp(state, "recovery") != 0 && strcmp(state, "sideload") != 0) {
+        fprintf(stderr, "adb: unknown state %s; "
+                        "expected 'bootloader', 'device', 'recovery', or 'sideload'\n", state);
+        return false;
+    }
+    return true;
+}
+
 static bool wait_for_device(const char* service, TransportType t, const char* serial) {
     // Was the caller vague about what they'd like us to wait for?
     // If so, check they weren't more specific in their choice of transport type.
     if (strcmp(service, "wait-for-device") == 0) {
         if (t == kTransportUsb) {
-            service = "wait-for-usb";
+            service = "wait-for-usb-device";
         } else if (t == kTransportLocal) {
-            service = "wait-for-local";
+            service = "wait-for-local-device";
         } else {
-            service = "wait-for-any";
+            service = "wait-for-any-device";
         }
     }
 
+    if (!check_wait_for_device_syntax(service)) {
+        return false;
+    }
+
     std::string cmd = format_host_command(service, t, serial);
     return adb_command(cmd);
 }
diff --git a/adb/services.cpp b/adb/services.cpp
index 523353a..20166ce 100644
--- a/adb/services.cpp
+++ b/adb/services.cpp
@@ -356,19 +356,19 @@
 #if ADB_HOST
 struct state_info {
     TransportType transport_type;
-    char* serial;
+    std::string serial;
     ConnectionState state;
 };
 
-static void wait_for_state(int fd, void* cookie) {
-    state_info* sinfo = reinterpret_cast<state_info*>(cookie);
+static void wait_for_state(int fd, void* data) {
+    std::unique_ptr<state_info> sinfo(reinterpret_cast<state_info*>(data));
 
     D("wait_for_state %d", sinfo->state);
 
     while (true) {
         bool is_ambiguous = false;
         std::string error = "unknown error";
-        atransport* t = acquire_one_transport(sinfo->transport_type, sinfo->serial,
+        atransport* t = acquire_one_transport(sinfo->transport_type, sinfo->serial.c_str(),
                                               &is_ambiguous, &error);
         if (t != nullptr && t->connection_state == sinfo->state) {
             SendOkay(fd);
@@ -382,10 +382,6 @@
         }
     }
 
-    if (sinfo->serial) {
-        free(sinfo->serial);
-    }
-    free(sinfo);
     adb_close(fd);
     D("wait_for_state is done");
 }
@@ -491,38 +487,43 @@
 asocket* host_service_to_socket(const char* name, const char* serial) {
     if (!strcmp(name,"track-devices")) {
         return create_device_tracker();
-    } else if (!strncmp(name, "wait-for-", strlen("wait-for-"))) {
-        auto sinfo = reinterpret_cast<state_info*>(malloc(sizeof(state_info)));
-        if (sinfo == nullptr) {
-            fprintf(stderr, "couldn't allocate state_info: %s", strerror(errno));
-            return NULL;
-        }
-
-        if (serial)
-            sinfo->serial = strdup(serial);
-        else
-            sinfo->serial = NULL;
-
+    } else if (android::base::StartsWith(name, "wait-for-")) {
         name += strlen("wait-for-");
 
-        if (!strncmp(name, "local", strlen("local"))) {
-            sinfo->transport_type = kTransportLocal;
-            sinfo->state = kCsDevice;
-        } else if (!strncmp(name, "usb", strlen("usb"))) {
-            sinfo->transport_type = kTransportUsb;
-            sinfo->state = kCsDevice;
-        } else if (!strncmp(name, "any", strlen("any"))) {
-            sinfo->transport_type = kTransportAny;
-            sinfo->state = kCsDevice;
-        } else {
-            if (sinfo->serial) {
-                free(sinfo->serial);
-            }
-            free(sinfo);
-            return NULL;
+        std::unique_ptr<state_info> sinfo(new state_info);
+        if (sinfo == nullptr) {
+            fprintf(stderr, "couldn't allocate state_info: %s", strerror(errno));
+            return nullptr;
         }
 
-        int fd = create_service_thread(wait_for_state, sinfo);
+        if (serial) sinfo->serial = serial;
+
+        if (android::base::StartsWith(name, "local")) {
+            name += strlen("local");
+            sinfo->transport_type = kTransportLocal;
+        } else if (android::base::StartsWith(name, "usb")) {
+            name += strlen("usb");
+            sinfo->transport_type = kTransportUsb;
+        } else if (android::base::StartsWith(name, "any")) {
+            name += strlen("any");
+            sinfo->transport_type = kTransportAny;
+        } else {
+            return nullptr;
+        }
+
+        if (!strcmp(name, "-device")) {
+            sinfo->state = kCsDevice;
+        } else if (!strcmp(name, "-recovery")) {
+            sinfo->state = kCsRecovery;
+        } else if (!strcmp(name, "-sideload")) {
+            sinfo->state = kCsSideload;
+        } else if (!strcmp(name, "-bootloader")) {
+            sinfo->state = kCsBootloader;
+        } else {
+            return nullptr;
+        }
+
+        int fd = create_service_thread(wait_for_state, sinfo.release());
         return create_local_socket(fd);
     } else if (!strncmp(name, "connect:", 8)) {
         char* host = strdup(name + 8);