diff --git a/src/lib-sieve/sieve-script-private.h b/src/lib-sieve/sieve-script-private.h
index 6e93fca86..e15d358ff 100644
--- a/src/lib-sieve/sieve-script-private.h
+++ b/src/lib-sieve/sieve-script-private.h
@@ -27,7 +27,7 @@ struct sieve_script_vfuncs {
 			sieve_size_t *offset);
 	void (*binary_write_metadata)
 		(struct sieve_script *script, struct sieve_binary_block *sblock);
-	int (*binary_dump_metadata)
+	bool (*binary_dump_metadata)
 		(struct sieve_script *script, struct sieve_dumptime_env *denv,
 			struct sieve_binary_block *sblock, sieve_size_t *offset);
 	struct sieve_binary *(*binary_load)
diff --git a/src/lib-sieve/storage/dict/sieve-dict-script.c b/src/lib-sieve/storage/dict/sieve-dict-script.c
index 43e566228..ea2842667 100644
--- a/src/lib-sieve/storage/dict/sieve-dict-script.c
+++ b/src/lib-sieve/storage/dict/sieve-dict-script.c
@@ -182,7 +182,7 @@ static void sieve_dict_script_binary_write_metadata
 	sieve_binary_emit_cstring(sblock, dscript->data_id);
 }
 
-static int sieve_dict_script_binary_dump_metadata
+static bool sieve_dict_script_binary_dump_metadata
 (struct sieve_script *script ATTR_UNUSED, struct sieve_dumptime_env *denv,
 	struct sieve_binary_block *sblock, sieve_size_t *offset)
 {
diff --git a/src/lib-sieve/storage/ldap/sieve-ldap-script.c b/src/lib-sieve/storage/ldap/sieve-ldap-script.c
index e16629832..7af8bf865 100644
--- a/src/lib-sieve/storage/ldap/sieve-ldap-script.c
+++ b/src/lib-sieve/storage/ldap/sieve-ldap-script.c
@@ -211,7 +211,7 @@ static void sieve_ldap_script_binary_write_metadata
 		sieve_binary_emit_cstring(sblock, lscript->modattr);
 }
 
-static int sieve_ldap_script_binary_dump_metadata
+static bool sieve_ldap_script_binary_dump_metadata
 (struct sieve_script *script ATTR_UNUSED, struct sieve_dumptime_env *denv,
 	struct sieve_binary_block *sblock, sieve_size_t *offset)
 {