diff --git a/src/vim9compile.c b/src/vim9compile.c
index d6fc6d8..ff96b10 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -3043,7 +3043,25 @@
     }
     else
     {
-	emsg(_(e_string_list_dict_or_blob_required));
+	switch (vartype)
+	{
+	    case VAR_FUNC:
+	    case VAR_PARTIAL:
+		emsg(_(e_cannot_index_a_funcref));
+		break;
+	    case VAR_BOOL:
+	    case VAR_SPECIAL:
+	    case VAR_JOB:
+	    case VAR_CHANNEL:
+	    case VAR_INSTR:
+	    case VAR_UNKNOWN:
+	    case VAR_ANY:
+	    case VAR_VOID:
+		emsg(_(e_cannot_index_special_variable));
+		break;
+	    default:
+		emsg(_(e_string_list_dict_or_blob_required));
+	}
 	return FAIL;
     }
     return OK;