diff --git a/tile.cpp b/tile.cpp
index d76ac126..82d2fb63 100644
--- a/tile.cpp
+++ b/tile.cpp
@@ -1206,11 +1206,12 @@ struct write_tile_args {
 	std::vector<std::map<std::string, layermap_entry>> *layermaps;
 	std::vector<std::vector<std::string>> *layer_unmaps;
 	size_t pass;
+	size_t passes;
 	unsigned long long mingap;
 	unsigned long long mingap_out;
 };
 
-long long write_tile(FILE *geoms, long long *geompos_in, char *metabase, char *stringpool, int z, unsigned tx, unsigned ty, int detail, int min_detail, int basezoom, sqlite3 *outdb, double droprate, int buffer, const char *fname, FILE **geomfile, int minzoom, int maxzoom, double todo, volatile long long *along, long long alongminus, double gamma, int child_shards, long long *meta_off, long long *pool_off, unsigned *initial_x, unsigned *initial_y, volatile int *running, double simplification, std::vector<std::map<std::string, layermap_entry>> *layermaps, std::vector<std::vector<std::string>> *layer_unmaps, size_t pass, unsigned long long mingap, write_tile_args *arg) {
+long long write_tile(FILE *geoms, long long *geompos_in, char *metabase, char *stringpool, int z, unsigned tx, unsigned ty, int detail, int min_detail, int basezoom, sqlite3 *outdb, double droprate, int buffer, const char *fname, FILE **geomfile, int minzoom, int maxzoom, double todo, volatile long long *along, long long alongminus, double gamma, int child_shards, long long *meta_off, long long *pool_off, unsigned *initial_x, unsigned *initial_y, volatile int *running, double simplification, std::vector<std::map<std::string, layermap_entry>> *layermaps, std::vector<std::vector<std::string>> *layer_unmaps, size_t pass, size_t passes, unsigned long long mingap, write_tile_args *arg) {
 	int line_detail;
 	double fraction = 1;
 	double merge_fraction = 1;
@@ -1346,7 +1347,7 @@ long long write_tile(FILE *geoms, long long *geompos_in, char *metabase, char *s
 			signed char feature_minzoom;
 			deserialize_byte_io(geoms, &feature_minzoom, geompos_in);
 
-			double progress = floor((((*geompos_in + *along - alongminus) / (double) todo) + z) / (maxzoom + 1) * 1000) / 10;
+			double progress = floor(((((*geompos_in + *along - alongminus) / (double) todo) + (pass - (2 - passes))) / passes + z) / (maxzoom + 1) * 1000) / 10;
 			if (progress >= oprogress + 0.1) {
 				if (!quiet) {
 					fprintf(stderr, "  %3.1f%%  %d/%u/%u  \r", progress, z, tx, ty);
@@ -1728,7 +1729,7 @@ long long write_tile(FILE *geoms, long long *geompos_in, char *metabase, char *s
 			totalsize += layer_features.size();
 		}
 
-		double progress = floor((((*geompos_in + *along - alongminus) / (double) todo) + z) / (maxzoom + 1) * 1000) / 10;
+		double progress = floor(((((*geompos_in + *along - alongminus) / (double) todo) + (pass - (2 - passes))) / passes + z) / (maxzoom + 1) * 1000) / 10;
 		if (progress >= oprogress + 0.1) {
 			if (!quiet) {
 				fprintf(stderr, "  %3.1f%%  %d/%u/%u  \r", progress, z, tx, ty);
@@ -1898,7 +1899,7 @@ void *run_thread(void *vargs) {
 
 			// fprintf(stderr, "%d/%u/%u\n", z, x, y);
 
-			long long len = write_tile(geom, &geompos, arg->metabase, arg->stringpool, z, x, y, z == arg->maxzoom ? arg->full_detail : arg->low_detail, arg->min_detail, arg->basezoom, arg->outdb, arg->droprate, arg->buffer, arg->fname, arg->geomfile, arg->minzoom, arg->maxzoom, arg->todo, arg->along, geompos, arg->gamma, arg->child_shards, arg->meta_off, arg->pool_off, arg->initial_x, arg->initial_y, arg->running, arg->simplification, arg->layermaps, arg->layer_unmaps, arg->pass, arg->mingap, arg);
+			long long len = write_tile(geom, &geompos, arg->metabase, arg->stringpool, z, x, y, z == arg->maxzoom ? arg->full_detail : arg->low_detail, arg->min_detail, arg->basezoom, arg->outdb, arg->droprate, arg->buffer, arg->fname, arg->geomfile, arg->minzoom, arg->maxzoom, arg->todo, arg->along, geompos, arg->gamma, arg->child_shards, arg->meta_off, arg->pool_off, arg->initial_x, arg->initial_y, arg->running, arg->simplification, arg->layermaps, arg->layer_unmaps, arg->pass, arg->passes, arg->mingap, arg);
 
 			if (len < 0) {
 				int *err = &arg->err;
@@ -2002,7 +2003,6 @@ int traverse_zooms(int *geomfd, off_t *geom_size, char *metabase, char *stringpo
 
 		size_t useful_threads = 0;
 		long long todo = 0;
-		long long along = 0;
 		for (size_t j = 0; j < TEMP_FILES; j++) {
 			todo += geom_size[j];
 			if (geom_size[j] > 0) {
@@ -2089,6 +2089,7 @@ int traverse_zooms(int *geomfd, off_t *geom_size, char *metabase, char *stringpo
 			pthread_t pthreads[threads];
 			write_tile_args args[threads];
 			int running = threads;
+			long long along = 0;
 
 			for (size_t thread = 0; thread < threads; thread++) {
 				args[thread].metabase = metabase;
@@ -2128,6 +2129,7 @@ int traverse_zooms(int *geomfd, off_t *geom_size, char *metabase, char *stringpo
 				args[thread].tasks = dispatches[thread].tasks;
 				args[thread].running = &running;
 				args[thread].pass = pass;
+				args[thread].passes = 2 - start;
 
 				if (pthread_create(&pthreads[thread], NULL, run_thread, &args[thread]) != 0) {
 					perror("pthread_create");