diff --git a/adb/client/usb_linux.cpp b/adb/client/usb_linux.cpp
index a7df0ed..1f376a4 100644
--- a/adb/client/usb_linux.cpp
+++ b/adb/client/usb_linux.cpp
@@ -253,7 +253,7 @@
                             continue;
                         }
                             /* aproto 01 needs 0 termination */
-                        if (interface->bInterfaceProtocol == 0x01) {
+                        if (interface->bInterfaceProtocol == ADB_PROTOCOL) {
                             max_packet_size = ep1->wMaxPacketSize;
                             zero_mask = ep1->wMaxPacketSize - 1;
                         }
diff --git a/adb/client/usb_osx.cpp b/adb/client/usb_osx.cpp
index 4e1480f..2e999ee 100644
--- a/adb/client/usb_osx.cpp
+++ b/adb/client/usb_osx.cpp
@@ -174,7 +174,7 @@
         kr = (*iface)->GetInterfaceClass(iface, &if_class);
         kr = (*iface)->GetInterfaceSubClass(iface, &subclass);
         kr = (*iface)->GetInterfaceProtocol(iface, &protocol);
-        if(if_class != ADB_CLASS || subclass != ADB_SUBCLASS || protocol != ADB_PROTOCOL) {
+        if (!is_adb_interface(if_class, subclass, protocol)) {
             // Ignore non-ADB devices.
             LOG(DEBUG) << "Ignoring interface with incorrect class/subclass/protocol - " << if_class
                        << ", " << subclass << ", " << protocol;
diff --git a/adb/client/usb_windows.cpp b/adb/client/usb_windows.cpp
index aff5229..61981b1 100644
--- a/adb/client/usb_windows.cpp
+++ b/adb/client/usb_windows.cpp
@@ -531,25 +531,23 @@
         return 0;
     }
 
-    if (is_adb_interface(interf_desc.bInterfaceClass, interf_desc.bInterfaceSubClass,
-                         interf_desc.bInterfaceProtocol)) {
-        if (interf_desc.bInterfaceProtocol == 0x01) {
-            AdbEndpointInformation endpoint_info;
-            // assuming zero is a valid bulk endpoint ID
-            if (AdbGetEndpointInformation(handle->adb_interface, 0, &endpoint_info)) {
-                handle->max_packet_size = endpoint_info.max_packet_size;
-                handle->zero_mask = endpoint_info.max_packet_size - 1;
-                D("device zero_mask: 0x%x", handle->zero_mask);
-            } else {
-                D("AdbGetEndpointInformation failed: %s",
-                  android::base::SystemErrorCodeToString(GetLastError()).c_str());
-            }
-        }
-
-        return 1;
+    if (!is_adb_interface(interf_desc.bInterfaceClass, interf_desc.bInterfaceSubClass,
+                          interf_desc.bInterfaceProtocol)) {
+        return 0;
     }
 
-    return 0;
+    AdbEndpointInformation endpoint_info;
+    // assuming zero is a valid bulk endpoint ID
+    if (AdbGetEndpointInformation(handle->adb_interface, 0, &endpoint_info)) {
+        handle->max_packet_size = endpoint_info.max_packet_size;
+        handle->zero_mask = endpoint_info.max_packet_size - 1;
+        D("device zero_mask: 0x%x", handle->zero_mask);
+    } else {
+        D("AdbGetEndpointInformation failed: %s",
+          android::base::SystemErrorCodeToString(GetLastError()).c_str());
+    }
+
+    return 1;
 }
 
 void find_devices() {