diff --git a/headers/os/drivers/PCI.h b/headers/os/drivers/PCI.h
index da33102b62..3cfd6eae5b 100644
--- a/headers/os/drivers/PCI.h
+++ b/headers/os/drivers/PCI.h
@@ -480,6 +480,7 @@ struct pci_module_info {
 
 #define PCI_usb_uhci			0x00	/* Universal Host Controller Interface */
 #define PCI_usb_ohci			0x10	/* Open Host Controller Interface */
+#define PCI_usb_ehci			0x20	/* Enhanced Host Controller Interface */
 
 
 /* ---
diff --git a/src/add-ons/kernel/busses/usb/ehci.cpp b/src/add-ons/kernel/busses/usb/ehci.cpp
index 8e5b7fb9d2..db9f41693d 100644
--- a/src/add-ons/kernel/busses/usb/ehci.cpp
+++ b/src/add-ons/kernel/busses/usb/ehci.cpp
@@ -256,9 +256,9 @@ EHCI::AddTo(Stack *stack)
 	}
 
 	for (int32 i = 0; sPCIModule->get_nth_pci_info(i, item) >= B_OK; i++) {
-		// class_base: 0C (Serial Bus); class_sub: 03 (USB); class_api: 20 (EHCI)
-		if (item->class_base == 0x0C && item->class_sub == 0x03
-			&& item->class_api == 0x20) {
+
+		if (item->class_base == PCI_serial_bus && item->class_sub == PCI_usb
+			&& item->class_api == PCI_usb_ehci) {
 			if (item->u.h0.interrupt_line == 0
 				|| item->u.h0.interrupt_line == 0xFF) {
 				TRACE_ERROR(("usb_ehci: found device with invalid IRQ - check IRQ assignement\n"));
diff --git a/src/add-ons/kernel/busses/usb/ohci.cpp b/src/add-ons/kernel/busses/usb/ohci.cpp
index 14993ee12e..0c7d3d7d21 100644
--- a/src/add-ons/kernel/busses/usb/ohci.cpp
+++ b/src/add-ons/kernel/busses/usb/ohci.cpp
@@ -115,11 +115,8 @@ ohci_add_to( Stack *stack )
 	item = new pci_info;
 	for ( i = 0 ; OHCI::pci_module->get_nth_pci_info( i , item ) == B_OK ; i++ )
 	{
-		//
-		//	class_base = 0C (serial bus) class_sub = 03 (usb) prog_int: 10 (OHCI)
-		//
-		if ( ( item->class_base == 0x0C ) && ( item->class_sub == 0x03 ) &&
-			 ( item->class_api  == 0x10 ) )
+		if ( ( item->class_base == PCI_serial_bus ) && ( item->class_sub == PCI_usb ) &&
+			 ( item->class_api  == PCI_usb_ohci ) )
 		{
 			if ((item->u.h0.interrupt_line == 0) || (item->u.h0.interrupt_line == 0xFF)) 
 			{
diff --git a/src/add-ons/kernel/busses/usb/uhci.cpp b/src/add-ons/kernel/busses/usb/uhci.cpp
index 6e6fcbcd12..a9b0b146f5 100644
--- a/src/add-ons/kernel/busses/usb/uhci.cpp
+++ b/src/add-ons/kernel/busses/usb/uhci.cpp
@@ -1052,9 +1052,9 @@ UHCI::AddTo(Stack *stack)
 	}
 
 	for (int32 i = 0; sPCIModule->get_nth_pci_info(i, item) >= B_OK; i++) {
-		//class_base = 0C (serial bus) class_sub = 03 (usb) prog_int: 00 (UHCI)
-		if (item->class_base == 0x0C && item->class_sub == 0x03
-			&& item->class_api == 0x00) {
+
+		if (item->class_base == PCI_serial_bus && item->class_sub == PCI_usb
+			&& item->class_api == PCI_usb_uhci) {
 			if (item->u.h0.interrupt_line == 0
 				|| item->u.h0.interrupt_line == 0xFF) {
 				TRACE_ERROR(("usb_uhci: AddTo(): found with invalid IRQ - check IRQ assignement\n"));