--- a/src/debug.cpp
+++ b/src/debug.cpp
@@ -73,6 +73,31 @@
 	};
 #undef DEBUG_LEVEL
 
+/**
+ * Dump the available debug facility names in the help text.
+ * @param buf Start address for storing the output.
+ * @param last Last valid address for storing the output.
+ * @return Next free position in the output.
+ */
+char *DumpDebugFacilityNames(char *buf, char *last)
+{
+	int length = 0;
+	for (const DebugLevel *i = debug_level; i != endof(debug_level); ++i) {
+		if (length == 0) {
+			buf = strecpy(buf, "List of debug facility names:\n", last);
+		} else {
+			buf = strecpy(buf, ", ", last);
+			length += 2;
+		}
+		buf = strecpy(buf, i->name, last);
+		length += strlen(i->name);
+	}
+	if (length > 0) {
+		buf = strecpy(buf, "\n\n", last);
+	}
+	return buf;
+}
+
 #if !defined(NO_DEBUG_MESSAGES)
 
 /**

--- a/src/debug.h
+++ b/src/debug.h
@@ -58,6 +58,7 @@
 	void CDECL debug(const char *dbg, const char *format, ...) WARN_FORMAT(2, 3);
 #endif /* NO_DEBUG_MESSAGES */
 
+char *DumpDebugFacilityNames(char *buf, char *last);
 void SetDebugString(const char *s);
 const char *GetDebugString();
 

--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -192,6 +192,9 @@
 	/* List the blitters */
 	p = BlitterFactoryBase::GetBlittersInfo(p, lastof(buf));
 
+	/* List the debug facilities. */
+	p = DumpDebugFacilityNames(p, lastof(buf));
+
 	/* We need to initialize the AI, so it finds the AIs */
 	AI::Initialize();
 	p = AI::GetConsoleList(p, lastof(buf), true);