diff --git a/include/pe.h b/include/pe.h
index deb35a0..4ef3e92 100644
--- a/include/pe.h
+++ b/include/pe.h
@@ -62,6 +62,12 @@
 
 #define IMAGE_NUMBEROF_DIRECTORY_ENTRIES 16
 
+/* PE32+ Subsystem type for EFI images */
+#define IMAGE_SUBSYSTEM_EFI_APPLICATION         10
+#define IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER 11
+#define IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER      12
+#define IMAGE_SUBSYSTEM_SAL_RUNTIME_DRIVER      13
+
 typedef struct _IMAGE_OPTIONAL_HEADER64 {
 	uint16_t Magic; /* 0x20b */
 	uint8_t  MajorLinkerVersion;