diff --git a/degesch.c b/degesch.c
index bc70a7a..5dc902c 100644
--- a/degesch.c
+++ b/degesch.c
@@ -4147,20 +4147,20 @@ static char *
 irc_process_hooks (struct server *s, char *input)
 {
 	log_server_debug (s, "#a>> \"#S\"#r", ATTR_JOIN, input);
+	uint64_t hash = siphash_wrapper (input, strlen (input));
 	LIST_FOR_EACH (struct hook, iter, s->ctx->irc_hooks)
 	{
 		struct irc_hook *hook = (struct irc_hook *) iter;
-		char *processed = hook->vtable->filter (hook, s, input);
-		if (input == processed)
-			continue;
-
-		if (processed == NULL)
+		if (!(input = hook->vtable->filter (hook, s, input)))
 		{
 			log_server_debug (s, "#a>= #s#r", ATTR_JOIN, "thrown away by hook");
 			return NULL;
 		}
 
-		log_server_debug (s, "#a>= \"#S\"#r", ATTR_JOIN, (input = processed));
+		uint64_t new_hash = siphash_wrapper (input, strlen (input));
+		if (new_hash != hash)
+			log_server_debug (s, "#a>= \"#S\"#r", ATTR_JOIN, input);
+		hash = new_hash;
 	}
 	return input;
 }
@@ -9546,21 +9546,20 @@ static char *
 process_input_hooks (struct app_context *ctx, struct buffer *buffer,
 	char *input)
 {
+	uint64_t hash = siphash_wrapper (input, strlen (input));
 	LIST_FOR_EACH (struct hook, iter, ctx->input_hooks)
 	{
 		struct input_hook *hook = (struct input_hook *) iter;
-		char *processed = hook->vtable->filter (hook, buffer, input);
-		if (input == processed)
-			continue;
-
-		if (processed == NULL)
+		if (!(input = hook->vtable->filter (hook, buffer, input)))
 		{
 			log_global_debug (ctx, "Input thrown away by hook");
 			return NULL;
 		}
 
-		log_global_debug (ctx,
-			"Input transformed to \"#s\"#r", (input = processed));
+		uint64_t new_hash = siphash_wrapper (input, strlen (input));
+		if (new_hash != hash)
+			log_global_debug (ctx, "Input transformed to \"#s\"#r", input);
+		hash = new_hash;
 	}
 	return input;
 }