diff --git a/ChangeLog b/ChangeLog
index d832f022..c268e79d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,6 @@
 9/11/22 started 8.13.4
 - missing include in mosaic_fuzzer [ServOKio]
+- emit "finish" at the end of targetcustom write [lucaskanashiro]
 
 11/10/22 started 8.13.3
 - improve rules for 16-bit heifsave [johntrunc]
diff --git a/libvips/iofuncs/targetcustom.c b/libvips/iofuncs/targetcustom.c
index 603422d5..82237458 100644
--- a/libvips/iofuncs/targetcustom.c
+++ b/libvips/iofuncs/targetcustom.c
@@ -161,6 +161,11 @@ vips_target_custom_end_real( VipsTarget *target )
 
 	VIPS_DEBUG_MSG( "vips_target_custom_end_real:\n" );
 
+	/* For compatibility with oklder libvipses, we have to emit "finish"
+	 * as well. ruby-vips relies on this.
+	 */
+	g_signal_emit( target, vips_target_custom_signals[SIG_FINISH], 0 );
+
 	/* Return value if no attached handler.
 	 */
 	result = 0;