diff --git a/proto/ei-proto.h.tmpl b/proto/ei-proto.h.tmpl
index cd0af45..e86bd59 100644
--- a/proto/ei-proto.h.tmpl
+++ b/proto/ei-proto.h.tmpl
@@ -61,6 +61,10 @@ enum {{enum.fqdn}} {
 	{{enum.fqdn.upper()}}_{{entry.name.upper()}} = {{entry.value}},
 	{% endfor %}
 };
+
+{% for entry in enum.entries %}
+#define {{enum.fqdn.upper()}}_{{entry.name.upper()}}_SINCE_VERSION {{entry.since}}
+{% endfor %}
 {% endfor %}
 
 /* Message sender functions */
diff --git a/proto/scanner.py b/proto/scanner.py
index 83ac6d1..3aaccfb 100755
--- a/proto/scanner.py
+++ b/proto/scanner.py
@@ -221,10 +221,13 @@ class Entry:
     name: str = attr.ib()
     value: int = attr.ib()
     summary: str = attr.ib()
+    since: int = attr.ib()
 
     @classmethod
-    def create(cls, name: str, value: int, summary: str = "") -> "Entry":
-        return cls(name=name, value=value, summary=summary)
+    def create(
+        cls, name: str, value: int, summary: str = "", since: int = 1
+    ) -> "Entry":
+        return cls(name=name, value=value, summary=summary, since=since)
 
 
 @attr.s
@@ -549,7 +552,8 @@ class Protocol(xml.sax.handler.ContentHandler):
             name = attrs["name"]
             value = int(attrs["value"])
             summary = attrs.get("summary", "")
-            entry = Entry.create(name=name, value=value, summary=summary)
+            since = int(attrs.get("since", 1))
+            entry = Entry.create(name=name, value=value, summary=summary, since=since)
             try:
                 self.current_message.add_entry(entry)
             except ValueError as e: