diff --git a/src/include/firebird/FirebirdInterface.idl b/src/include/firebird/FirebirdInterface.idl
index 751718527f..b2bc63c1ee 100644
--- a/src/include/firebird/FirebirdInterface.idl
+++ b/src/include/firebird/FirebirdInterface.idl
@@ -28,7 +28,6 @@
 
 struct ISC_QUAD;
 struct FbCryptKey;
-struct DtcStart;
 
 // Versioned interface - base for all FB interfaces
 interface Versioned