diff --git a/Makefile b/Makefile
index ea4e976..5ce1798 100644
--- a/Makefile
+++ b/Makefile
@@ -13,7 +13,6 @@ PGFILEDESC = "pg_query_state - facility to track progress of plan execution"
 EXTRA_CLEAN = ./isolation_output $(EXTENSION)--$(EXTVERSION).sql \
 	Dockerfile ./tests/*.pyc ./tmp_stress
 
-ISOLATION = corner_cases
 ISOLATION_OPTS = --load-extension=pg_query_state
 
 TAP_TESTS = 1
diff --git a/pg_query_state.h b/pg_query_state.h
index f632008..805e144 100644
--- a/pg_query_state.h
+++ b/pg_query_state.h
@@ -12,7 +12,11 @@
 
 #include <postgres.h>
 
+#if PG_VERSION_NUM >= 180000
+#include "commands/explain_state.h"
+#else
 #include "commands/explain.h"
+#endif
 #include "nodes/pg_list.h"
 #include "storage/procarray.h"
 #include "storage/shm_mq.h"
diff --git a/signal_handler.c b/signal_handler.c
index dfe8780..1e20787 100644
--- a/signal_handler.c
+++ b/signal_handler.c
@@ -11,6 +11,9 @@
 #include "pg_query_state.h"
 
 #include "commands/explain.h"
+#if PG_VERSION_NUM >= 180000
+#include "commands/explain_format.h"
+#endif
 #include "miscadmin.h"
 #if PG_VERSION_NUM >= 100000
 #include "pgstat.h"