diff --git a/IV/Makefile b/IV/Makefile
index 1209b19..709e1ba 100644
--- a/IV/Makefile
+++ b/IV/Makefile
@@ -5,9 +5,9 @@ WHERE ?= name='Visinčia' OR name='Šalčia' OR name='Nemunas'
 test: tests.sql .faux.db
 	./db -f tests.sql
 
-.PHONY: integration-test
-integration-test: .faux_filter_rivers
-	./db -f integration-tests.sql
+.PHONY: test-integration
+test-integration: .faux_filter-rivers
+	./db -f tests-integration.sql
 
 .faux_filter-rivers: .faux_import-osm
 	./db -v where="$(WHERE)" -f aggregate-rivers.sql
diff --git a/IV/aggregate-rivers.sql b/IV/aggregate-rivers.sql
index 77ad483..7d091f6 100644
--- a/IV/aggregate-rivers.sql
+++ b/IV/aggregate-rivers.sql
@@ -24,7 +24,7 @@ begin
 end
 $$ language plpgsql;
 
-create temporary table aggregate_rivers_tmp (osm_id bigint, name text, way geometry);
+create temporary table aggregate_rivers_tmp (osm_id bigint, name text, way geometry) on commit drop;
 create index aggregate_rivers_tmp_id on aggregate_rivers_tmp(osm_id);
 create index aggregate_rivers_tmp_gix on aggregate_rivers_tmp using gist(way) include(name);
 
@@ -34,4 +34,3 @@ insert into aggregate_rivers_tmp
 
 drop table if exists agg_rivers;
 create table agg_rivers as (select * from aggregate_rivers());
-drop table aggregate_rivers_tmp;
diff --git a/IV/tests-integration.sql b/IV/tests-integration.sql
new file mode 100644
index 0000000..ab6310f
--- /dev/null
+++ b/IV/tests-integration.sql
@@ -0,0 +1,3 @@
+\i wm.sql
+
+select ST_SimplifyWM_DEBUG(way) from agg_rivers;
diff --git a/IV/wm.sql b/IV/wm.sql
index 0de6415..fddeb65 100644
--- a/IV/wm.sql
+++ b/IV/wm.sql
@@ -273,26 +273,27 @@ drop function if exists ST_SimplifyWM;
 create function ST_SimplifyWM(geom geometry) returns geometry as $$
 declare
   line geometry;
-  geoms geometry[];
+  lines geometry[];
   bends geometry[];
   mutated boolean;
   l_type text;
 begin
   l_type = st_geometrytype(geom);
   if l_type = 'ST_LineString' then
-    geoms = array[geom];
+    lines = array[geom];
   elseif l_type = 'ST_MultiLineString' then
-    geoms = array((select a.geom from st_dump(geom) a order by path[1] desc));
+    lines = array((select a.geom from st_dump(geom) a order by path[1] desc));
   else
     raise 'Unknown geometry type %', l_type;
   end if;
 
-  foreach line in array geoms loop
+  foreach line in array lines loop
     mutated = true;
     while mutated loop
       bends = detect_bends(line);
       bends = fix_gentle_inflections(bends);
       select * from self_crossing(bends) into bends, mutated;
+      line = st_linemerge(st_union(bends));
     end loop;
   end loop;
 
@@ -309,29 +310,43 @@ create function ST_SimplifyWM_DEBUG(geom geometry) returns geometry as $$
 declare
   i integer;
   line geometry;
-  geoms geometry[];
+  lines geometry[];
   bends geometry[];
   mutated boolean;
   l_type text;
 begin
   l_type = st_geometrytype(geom);
   if l_type = 'ST_LineString' then
-    geoms = array[geom];
+    lines = array[geom];
   elseif l_type = 'ST_MultiLineString' then
-    geoms = array((select a.geom from st_dump(geom) a order by path[1] desc));
+    lines = array((select a.geom from st_dump(geom) a order by path[1] desc));
   else
     raise 'Unknown geometry type %', l_type;
   end if;
 
   i = 1;
-  foreach line in array geoms loop
-    mutated = true;
+  mutated = true;
+  foreach line in array lines loop
     while mutated loop
-      execute format('create table figures_%I (name text, i bigint, way geometry)', i);
-      execute format('insert into figures_%I select name, generate_subscripts(ways)
+      execute format('drop table if exists demo_%sfigures0', i);
+      execute format('create table demo_%sfigures0 (way geometry)', i);
+      -- if anyone has suggestions how to insert a variable to a table without such
+      -- hackery, I'll be glad to know
+      execute format('insert into demo_%sfigures0 select $1;', i) using (select unnest(array[line]));
       bends = detect_bends(line);
+      execute format('drop table if exists demo_%sbends1', i);
+      execute format('create table demo_%sbends1 (i bigint, way geometry)', i);
+      execute format('insert into demo_%sbends1 (i, way) select generate_subscripts($1, 1), unnest($1)', i) using bends;
       bends = fix_gentle_inflections(bends);
+      execute format('drop table if exists demo_%sinflections2', i);
+      execute format('create table demo_%sinflections2 (i bigint, way geometry)', i);
+      execute format('insert into demo_%sinflections2 (i, way) select generate_subscripts($1, 1), unnest($1)', i) using bends;
       select * from self_crossing(bends) into bends, mutated;
+      execute format('drop table if exists demo_%sselfcrossing3', i);
+      execute format('create table demo_%sselfcrossing3 (i bigint, way geometry)', i);
+      execute format('insert into demo_%sselfcrossing3 (i, way) select generate_subscripts($1, 1), unnest($1)', i) using bends;
+      line = st_linemerge(st_union(bends));
+      i = i + 1;
     end loop;
   end loop;