diff --git a/plugin.cpp b/plugin.cpp
index ebb24889..c6a87617 100644
--- a/plugin.cpp
+++ b/plugin.cpp
@@ -400,7 +400,7 @@ serial_feature parse_feature(json_pull *jp, int z, unsigned x, unsigned y, std::
 			sf.index = 0;
 			sf.bbox[0] = sf.bbox[1] = LLONG_MAX;
 			sf.bbox[2] = sf.bbox[3] = LLONG_MIN;
-			sf.extent = 0;
+			sf.area = 0;
 			sf.metapos = 0;
 			sf.has_id = false;
 
@@ -422,9 +422,9 @@ serial_feature parse_feature(json_pull *jp, int z, unsigned x, unsigned y, std::
 					sf.seq = sequence->value.number.number;
 				}
 
-				json_object *extent = json_hash_get(tippecanoe, "extent");
-				if (extent != NULL && extent->type == JSON_NUMBER) {
-					sf.extent = extent->value.number.number;
+				json_object *area = json_hash_get(tippecanoe, "extent");
+				if (area != NULL && area->type == JSON_NUMBER) {
+					sf.area = area->value.number.number;
 				}
 
 				json_object *dropped = json_hash_get(tippecanoe, "dropped");
diff --git a/serial.cpp b/serial.cpp
index 27db34d0..f8d89e82 100644
--- a/serial.cpp
+++ b/serial.cpp
@@ -196,7 +196,7 @@ void serialize_feature(FILE *geomfile, serial_feature *sf, std::atomic<long long
 	layer |= sf->layer << 6;
 	layer |= (sf->seq != 0) << 5;
 	layer |= (sf->index != 0) << 4;
-	layer |= (sf->extent != 0) << 3;
+	layer |= (sf->area != 0) << 3;
 	layer |= sf->has_id << 2;
 	layer |= sf->has_tippecanoe_minzoom << 1;
 	layer |= sf->has_tippecanoe_maxzoom << 0;
@@ -222,8 +222,8 @@ void serialize_feature(FILE *geomfile, serial_feature *sf, std::atomic<long long
 	if (sf->index != 0) {
 		serialize_ulong_long(geomfile, sf->index, geompos, fname);
 	}
-	if (sf->extent != 0) {
-		serialize_long_long(geomfile, sf->extent, geompos, fname);
+	if (sf->area != 0) {
+		serialize_long_long(geomfile, sf->area, geompos, fname);
 	}
 
 	serialize_long_long(geomfile, sf->metapos, geompos, fname);
@@ -275,14 +275,14 @@ serial_feature deserialize_feature(FILE *geoms, std::atomic<long long> *geompos_
 	deserialize_int_io(geoms, &sf.segment, geompos_in);
 
 	sf.index = 0;
-	sf.extent = 0;
+	sf.area = 0;
 
 	sf.geometry = decode_geometry(geoms, geompos_in, z, tx, ty, sf.bbox, initial_x[sf.segment], initial_y[sf.segment]);
 	if (sf.layer & (1 << 4)) {
 		deserialize_ulong_long_io(geoms, &sf.index, geompos_in);
 	}
 	if (sf.layer & (1 << 3)) {
-		deserialize_long_long_io(geoms, &sf.extent, geompos_in);
+		deserialize_long_long_io(geoms, &sf.area, geompos_in);
 	}
 
 	sf.layer >>= 6;
@@ -503,12 +503,12 @@ int serialize_feature(struct serialization_state *sst, serial_feature &sf) {
 
 		if (prevent[P_CLIPPING]) {
 			static std::atomic<long long> warned(0);
-			long long extent = ((sf.bbox[2] - sf.bbox[0]) / ((1LL << (32 - sst->maxzoom)) + 1)) * ((sf.bbox[3] - sf.bbox[1]) / ((1LL << (32 - sst->maxzoom)) + 1));
-			if (extent > warned) {
-				fprintf(stderr, "Warning: %s:%d: Large unclipped (-pc) feature may be duplicated across %lld tiles\n", sst->fname, sst->line, extent);
-				warned = extent;
+			long long area = ((sf.bbox[2] - sf.bbox[0]) / ((1LL << (32 - sst->maxzoom)) + 1)) * ((sf.bbox[3] - sf.bbox[1]) / ((1LL << (32 - sst->maxzoom)) + 1));
+			if (area > warned) {
+				fprintf(stderr, "Warning: %s:%d: Large unclipped (-pc) feature may be duplicated across %lld tiles\n", sst->fname, sst->line, area);
+				warned = area;
 
-				if (extent > 10000) {
+				if (area > 10000) {
 					fprintf(stderr, "Exiting because this can't be right.\n");
 					exit(EXIT_IMPOSSIBLE);
 				}
@@ -516,7 +516,7 @@ int serialize_feature(struct serialization_state *sst, serial_feature &sf) {
 		}
 	}
 
-	double extent = 0;
+	double area = 0;
 	if (additional[A_DROP_SMALLEST_AS_NEEDED] || additional[A_COALESCE_SMALLEST_AS_NEEDED]) {
 		if (sf.t == VT_POLYGON) {
 			for (size_t i = 0; i < sf.geometry.size(); i++) {
@@ -528,7 +528,7 @@ int serialize_feature(struct serialization_state *sst, serial_feature &sf) {
 						}
 					}
 
-					extent += get_area(sf.geometry, i, j);
+					area += get_area(sf.geometry, i, j);
 					i = j - 1;
 				}
 			}
@@ -542,16 +542,16 @@ int serialize_feature(struct serialization_state *sst, serial_feature &sf) {
 				}
 			}
 			// treat lines as having the area of a circle with the line as diameter
-			extent = M_PI * (dist / 2) * (dist / 2);
+			area = M_PI * (dist / 2) * (dist / 2);
 		}
 
-		// VT_POINT extent will be calculated in write_tile from the distance between adjacent features.
+		// VT_POINT area will be calculated in write_tile from the distance between adjacent features.
 	}
 
-	if (extent <= LLONG_MAX) {
-		sf.extent = (long long) extent;
+	if (area <= LLONG_MAX) {
+		sf.area = (long long) area;
 	} else {
-		sf.extent = LLONG_MAX;
+		sf.area = LLONG_MAX;
 	}
 
 	if (!prevent[P_INPUT_ORDER]) {
diff --git a/serial.hpp b/serial.hpp
index a662d497..dfa506d2 100644
--- a/serial.hpp
+++ b/serial.hpp
@@ -56,7 +56,7 @@ struct serial_feature {
 
 	drawvec geometry = drawvec();
 	unsigned long long index = 0;
-	long long extent = 0;
+	long long area = 0;
 
 	std::vector<long long> keys{};
 	std::vector<long long> values{};
diff --git a/tile.cpp b/tile.cpp
index 0f9f81b4..29e1a59e 100644
--- a/tile.cpp
+++ b/tile.cpp
@@ -316,7 +316,7 @@ struct ordercmp {
 	}
 } ordercmp;
 
-void rewrite(drawvec &geom, int z, int nextzoom, int maxzoom, long long *bbox, unsigned tx, unsigned ty, int buffer, int *within, std::atomic<long long> *geompos, FILE **geomfile, const char *fname, signed char t, int layer, long long metastart, signed char feature_minzoom, int child_shards, int max_zoom_increment, long long seq, int tippecanoe_minzoom, int tippecanoe_maxzoom, int segment, unsigned *initial_x, unsigned *initial_y, std::vector<long long> &metakeys, std::vector<long long> &metavals, bool has_id, unsigned long long id, unsigned long long index, long long extent) {
+void rewrite(drawvec &geom, int z, int nextzoom, int maxzoom, long long *bbox, unsigned tx, unsigned ty, int buffer, int *within, std::atomic<long long> *geompos, FILE **geomfile, const char *fname, signed char t, int layer, long long metastart, signed char feature_minzoom, int child_shards, int max_zoom_increment, long long seq, int tippecanoe_minzoom, int tippecanoe_maxzoom, int segment, unsigned *initial_x, unsigned *initial_y, std::vector<long long> &metakeys, std::vector<long long> &metavals, bool has_id, unsigned long long id, unsigned long long index, long long area) {
 	if (geom.size() > 0 && (nextzoom <= maxzoom || additional[A_EXTEND_ZOOMS])) {
 		int xo, yo;
 		int span = 1 << (nextzoom - z);
@@ -406,7 +406,7 @@ void rewrite(drawvec &geom, int z, int nextzoom, int maxzoom, long long *bbox, u
 					sf.metapos = metastart;
 					sf.geometry = geom2;
 					sf.index = index;
-					sf.extent = extent;
+					sf.area = area;
 					sf.feature_minzoom = feature_minzoom;
 
 					if (metastart < 0) {
@@ -450,7 +450,7 @@ struct partial {
 	unsigned long long id = 0;
 	bool has_id = 0;
 	ssize_t renamed = 0;
-	long long extent = 0;
+	long long area = 0;
 	long long clustered = 0;
 	std::set<std::string> need_tilestats;
 	std::map<std::string, accum_state> attribute_accum_state;
@@ -1422,7 +1422,7 @@ serial_feature next_feature(FILE *geoms, std::atomic<long long> *geompos_in, cha
 
 		if (*first_time && pass == 1) { /* only write out the next zoom once, even if we retry */
 			if (sf.tippecanoe_maxzoom == -1 || sf.tippecanoe_maxzoom >= nextzoom) {
-				rewrite(sf.geometry, z, nextzoom, maxzoom, sf.bbox, tx, ty, buffer, within, geompos, geomfile, fname, sf.t, sf.layer, sf.metapos, sf.feature_minzoom, child_shards, max_zoom_increment, sf.seq, sf.tippecanoe_minzoom, sf.tippecanoe_maxzoom, sf.segment, initial_x, initial_y, sf.keys, sf.values, sf.has_id, sf.id, sf.index, sf.extent);
+				rewrite(sf.geometry, z, nextzoom, maxzoom, sf.bbox, tx, ty, buffer, within, geompos, geomfile, fname, sf.t, sf.layer, sf.metapos, sf.feature_minzoom, child_shards, max_zoom_increment, sf.seq, sf.tippecanoe_minzoom, sf.tippecanoe_maxzoom, sf.segment, initial_x, initial_y, sf.keys, sf.values, sf.has_id, sf.id, sf.index, sf.area);
 			}
 		}
 
@@ -1597,7 +1597,7 @@ void *run_prefilter(void *v) {
 		decode_meta(sf.keys, sf.values, rpa->stringpool + rpa->pool_off[sf.segment], tmp_layer, tmp_feature);
 		tmp_layer.features.push_back(tmp_feature);
 
-		layer_to_geojson(tmp_layer, 0, 0, 0, false, true, false, true, sf.index, sf.seq, sf.extent, true, state, 0);
+		layer_to_geojson(tmp_layer, 0, 0, 0, false, true, false, true, sf.index, sf.seq, sf.area, true, state, 0);
 	}
 
 	if (fclose(rpa->prefilter_fp) != 0) {
@@ -1951,12 +1951,12 @@ long long write_tile(FILE *geoms, std::atomic<long long> *geompos_in, char *meta
 
 			if (sf.t == VT_POINT) {
 				if (extent_previndex >= sf.index) {
-					sf.extent = 1;
+					sf.area = 1;
 				} else {
 					double radius = sqrt(sf.index - extent_previndex) / 4.0;
-					sf.extent = M_PI * radius * radius;
-					if (sf.extent < 1) {
-						sf.extent = 1;
+					sf.area = M_PI * radius * radius;
+					if (sf.area < 1) {
+						sf.area = 1;
 					}
 				}
 
@@ -2011,23 +2011,23 @@ long long write_tile(FILE *geoms, std::atomic<long long> *geompos_in, char *meta
 				indices.push_back(sf.index);
 				if (sf.index - merge_previndex < mingap && find_partial(partials, sf, which_partial, layer_unmaps)) {
 					partials[which_partial].geoms.push_back(sf.geometry);
-					coalesced_area += sf.extent;
+					coalesced_area += sf.area;
 					preserve_attributes(arg->attribute_accum, sf, stringpool, pool_off, partials[which_partial]);
 					strategy->coalesced_as_needed++;
 					continue;
 				}
 			} else if (additional[A_DROP_SMALLEST_AS_NEEDED]) {
-				extents.push_back(sf.extent);
-				if (sf.extent + coalesced_area <= minextent && find_partial(partials, sf, which_partial, layer_unmaps)) {
+				extents.push_back(sf.area);
+				if (sf.area + coalesced_area <= minextent && find_partial(partials, sf, which_partial, layer_unmaps)) {
 					preserve_attributes(arg->attribute_accum, sf, stringpool, pool_off, partials[which_partial]);
 					strategy->dropped_as_needed++;
 					continue;
 				}
 			} else if (additional[A_COALESCE_SMALLEST_AS_NEEDED]) {
-				extents.push_back(sf.extent);
-				if (sf.extent + coalesced_area <= minextent && find_partial(partials, sf, which_partial, layer_unmaps)) {
+				extents.push_back(sf.area);
+				if (sf.area + coalesced_area <= minextent && find_partial(partials, sf, which_partial, layer_unmaps)) {
 					partials[which_partial].geoms.push_back(sf.geometry);
-					coalesced_area += sf.extent;
+					coalesced_area += sf.area;
 					preserve_attributes(arg->attribute_accum, sf, stringpool, pool_off, partials[which_partial]);
 					strategy->coalesced_as_needed++;
 					continue;
@@ -2050,7 +2050,7 @@ long long write_tile(FILE *geoms, std::atomic<long long> *geompos_in, char *meta
 			if (fraction_accum < 1 && find_partial(partials, sf, which_partial, layer_unmaps)) {
 				if (additional[A_COALESCE_FRACTION_AS_NEEDED]) {
 					partials[which_partial].geoms.push_back(sf.geometry);
-					coalesced_area += sf.extent;
+					coalesced_area += sf.area;
 					strategy->coalesced_as_needed++;
 				} else {
 					strategy->dropped_as_needed++;
@@ -2116,7 +2116,7 @@ long long write_tile(FILE *geoms, std::atomic<long long> *geompos_in, char *meta
 					p.has_id = sf.has_id;
 					p.index = sf.index;
 					p.renamed = -1;
-					p.extent = sf.extent;
+					p.area = sf.area;
 					p.clustered = 0;
 
 					if (line_detail == detail && extra_detail >= 0 && z == maxzoom) {