diff --git a/reactos/tools/rsym/rsym.h b/reactos/tools/rsym/rsym.h
index 91b6c6d42b0..82261facec3 100644
--- a/reactos/tools/rsym/rsym.h
+++ b/reactos/tools/rsym/rsym.h
@@ -3,6 +3,9 @@
 #ifndef RSYM_H
 #define RSYM_H
 
+#define IMAGE_NT_OPTIONAL_HDR32_MAGIC 0x010b
+#define IMAGE_NT_OPTIONAL_HDR64_MAGIC 0x020b
+
 #define IMAGE_DOS_MAGIC 0x5a4d
 #define IMAGE_PE_MAGIC 0x00004550
 #define IMAGE_SIZEOF_SHORT_NAME 8