diff --git a/src/lib-dict-extra/dict-fs.c b/src/lib-dict-extra/dict-fs.c
index 82ea827308..bf1595f92c 100644
--- a/src/lib-dict-extra/dict-fs.c
+++ b/src/lib-dict-extra/dict-fs.c
@@ -258,7 +258,7 @@ static int fs_dict_write_changes(struct dict_transaction_memory_context *ctx)
 	return 0;
 }
 
-static int
+static void
 fs_dict_transaction_commit(struct dict_transaction_context *_ctx,
 			   bool async ATTR_UNUSED,
 			   dict_transaction_commit_callback_t *callback,
@@ -274,9 +274,7 @@ fs_dict_transaction_commit(struct dict_transaction_context *_ctx,
 		ret = 1;
 	pool_unref(&ctx->pool);
 
-	if (callback != NULL)
-		callback(ret, context);
-	return ret;
+	callback(ret, context);
 }
 
 struct dict dict_driver_fs = {
diff --git a/src/lib-dict/dict-client.c b/src/lib-dict/dict-client.c
index 40378c6016..bf9a370c2d 100644
--- a/src/lib-dict/dict-client.c
+++ b/src/lib-dict/dict-client.c
@@ -768,7 +768,7 @@ static void dict_async_input(struct client_dict *dict)
 	}
 }
 
-static int
+static void
 client_dict_transaction_commit(struct dict_transaction_context *_ctx,
 			       bool async,
 			       dict_transaction_commit_callback_t *callback,
@@ -799,6 +799,7 @@ client_dict_transaction_commit(struct dict_transaction_context *_ctx,
 				dict->io = io_add(dict->fd, IO_READ,
 						  dict_async_input, dict);
 			}
+			return;
 		} else {
 			/* sync commit, read reply */
 			if (client_dict_read_line(dict, &line, &error) < 0) {
@@ -830,14 +831,12 @@ client_dict_transaction_commit(struct dict_transaction_context *_ctx,
 			}
 		}
 	}
+	DLLIST_REMOVE(&dict->transactions, ctx);
 
-	if (ret < 0 || !async) {
-		DLLIST_REMOVE(&dict->transactions, ctx);
-		i_free(ctx);
+	callback(ret, context);
+	i_free(ctx);
 
-		client_dict_add_timeout(dict);
-	}
-	return ret;
+	client_dict_add_timeout(dict);
 }
 
 static void
diff --git a/src/lib-dict/dict-file.c b/src/lib-dict/dict-file.c
index 856453c625..615d2935eb 100644
--- a/src/lib-dict/dict-file.c
+++ b/src/lib-dict/dict-file.c
@@ -623,7 +623,7 @@ static int file_dict_write_changes(struct dict_transaction_memory_context *ctx,
 	return 0;
 }
 
-static int
+static void
 file_dict_transaction_commit(struct dict_transaction_context *_ctx,
 			     bool async ATTR_UNUSED,
 			     dict_transaction_commit_callback_t *callback,
@@ -642,9 +642,7 @@ file_dict_transaction_commit(struct dict_transaction_context *_ctx,
 		ret = 1;
 	pool_unref(&ctx->pool);
 
-	if (callback != NULL)
-		callback(ret, context);
-	return ret;
+	callback(ret, context);
 }
 
 struct dict dict_driver_file = {
diff --git a/src/lib-dict/dict-memcached-ascii.c b/src/lib-dict/dict-memcached-ascii.c
index 1bcaa02d5f..3d1e4571a1 100644
--- a/src/lib-dict/dict-memcached-ascii.c
+++ b/src/lib-dict/dict-memcached-ascii.c
@@ -610,7 +610,7 @@ memcached_ascii_transaction_send(struct dict_memcached_ascii_commit_ctx *ctx)
 	return 0;
 }
 
-static int
+static void
 memcached_ascii_transaction_commit(struct dict_transaction_context *_ctx,
 				   bool async,
 				   dict_transaction_commit_callback_t *callback,
@@ -637,7 +637,7 @@ memcached_ascii_transaction_commit(struct dict_transaction_context *_ctx,
 
 		if (async && ret == 0) {
 			pool_unref(&ctx->pool);
-			return 1;
+			return;
 		}
 
 		if (ret == 0) {
@@ -647,10 +647,8 @@ memcached_ascii_transaction_commit(struct dict_transaction_context *_ctx,
 			}
 		}
 	}
-	if (callback != NULL)
-		callback(ret, context);
+	callback(ret, context);
 	pool_unref(&ctx->pool);
-	return ret;
 }
 
 struct dict dict_driver_memcached_ascii = {
diff --git a/src/lib-dict/dict-private.h b/src/lib-dict/dict-private.h
index 16893e8ac4..049588d4da 100644
--- a/src/lib-dict/dict-private.h
+++ b/src/lib-dict/dict-private.h
@@ -23,10 +23,11 @@ struct dict_vfuncs {
 			      const char **error_r);
 
 	struct dict_transaction_context *(*transaction_init)(struct dict *dict);
-	int (*transaction_commit)(struct dict_transaction_context *ctx,
-				  bool async,
-				  dict_transaction_commit_callback_t *callback,
-				  void *context);
+	/* call the callback before returning if non-async commits */
+	void (*transaction_commit)(struct dict_transaction_context *ctx,
+				   bool async,
+				   dict_transaction_commit_callback_t *callback,
+				   void *context);
 	void (*transaction_rollback)(struct dict_transaction_context *ctx);
 
 	void (*set)(struct dict_transaction_context *ctx,
diff --git a/src/lib-dict/dict-redis.c b/src/lib-dict/dict-redis.c
index 5d16474898..2d38eb59c3 100644
--- a/src/lib-dict/dict-redis.c
+++ b/src/lib-dict/dict-redis.c
@@ -577,7 +577,7 @@ redis_transaction_init(struct dict *_dict)
 	return &ctx->ctx;
 }
 
-static int
+static void
 redis_transaction_commit(struct dict_transaction_context *_ctx, bool async,
 			 dict_transaction_commit_callback_t *callback,
 			 void *context)
@@ -610,14 +610,12 @@ redis_transaction_commit(struct dict_transaction_context *_ctx, bool async,
 			redis_input_state_add(dict, REDIS_INPUT_STATE_EXEC_REPLY);
 		if (async) {
 			i_free(ctx);
-			return 1;
+			return;
 		}
 		redis_wait(dict);
 	}
-	if (callback != NULL)
-		callback(ret, context);
+	callback(ret, context);
 	i_free(ctx);
-	return ret;
 }
 
 static void redis_transaction_rollback(struct dict_transaction_context *_ctx)
diff --git a/src/lib-dict/dict-sql.c b/src/lib-dict/dict-sql.c
index dcaea55ee1..2ba4179165 100644
--- a/src/lib-dict/dict-sql.c
+++ b/src/lib-dict/dict-sql.c
@@ -798,7 +798,7 @@ sql_dict_transaction_commit_callback(const char *error,
 	sql_dict_transaction_free(ctx);
 }
 
-static int
+static void
 sql_dict_transaction_commit(struct dict_transaction_context *_ctx, bool async,
 			    dict_transaction_commit_callback_t *callback,
 			    void *context)
@@ -822,7 +822,7 @@ sql_dict_transaction_commit(struct dict_transaction_context *_ctx, bool async,
 		ctx->async_context = context;
 		sql_transaction_commit(&ctx->sql_ctx,
 			sql_dict_transaction_commit_callback, ctx);
-		return 1;
+		return;
 	} else {
 		if (sql_transaction_commit_s(&ctx->sql_ctx, &error) < 0) {
 			i_error("sql dict: commit failed: %s", error);
@@ -834,9 +834,7 @@ sql_dict_transaction_commit(struct dict_transaction_context *_ctx, bool async,
 	}
 	sql_dict_transaction_free(ctx);
 
-	if (callback != NULL)
-		callback(ret, context);
-	return ret;
+	callback(ret, context);
 }
 
 static void sql_dict_transaction_rollback(struct dict_transaction_context *_ctx)
diff --git a/src/lib-dict/dict.c b/src/lib-dict/dict.c
index e8c4123650..e2ddff2e49 100644
--- a/src/lib-dict/dict.c
+++ b/src/lib-dict/dict.c
@@ -187,12 +187,21 @@ struct dict_transaction_context *dict_transaction_begin(struct dict *dict)
 	return dict->v.transaction_init(dict);
 }
 
+static void dict_transaction_commit_sync_callback(int ret, void *context)
+{
+	int *ret_p = context;
+	*ret_p = ret;
+}
+
 int dict_transaction_commit(struct dict_transaction_context **_ctx)
 {
 	struct dict_transaction_context *ctx = *_ctx;
+	int ret;
 
 	*_ctx = NULL;
-	return ctx->dict->v.transaction_commit(ctx, FALSE, NULL, NULL);
+	ctx->dict->v.transaction_commit(ctx, FALSE,
+		dict_transaction_commit_sync_callback, &ret);
+	return ret;
 }
 
 void dict_transaction_commit_async(struct dict_transaction_context **_ctx,