diff --git a/src/pl/plpgsql/src/Makefile b/src/pl/plpgsql/src/Makefile
index 70a9c34..193df8a 100644
--- a/src/pl/plpgsql/src/Makefile
+++ b/src/pl/plpgsql/src/Makefile
@@ -33,8 +33,8 @@ DATA = plpgsql.control plpgsql--1.0.sql
 REGRESS_OPTS = --dbname=$(PL_TESTDB)
 
 REGRESS = plpgsql_call plpgsql_control plpgsql_copy plpgsql_domain \
-	plpgsql_record plpgsql_cache plpgsql_transaction plpgsql_trap \
-	plpgsql_trigger plpgsql_varprops
+	plpgsql_record plpgsql_cache plpgsql_simple plpgsql_transaction \
+	plpgsql_trap plpgsql_trigger plpgsql_varprops
 
 # where to find gen_keywordlist.pl and subsidiary files
 TOOLSDIR = $(top_srcdir)/src/tools
diff --git a/src/pl/plpgsql/src/expected/plpgsql_simple.out b/src/pl/plpgsql/src/expected/plpgsql_simple.out
new file mode 100644
index 0000000..5a2fefa
--- /dev/null
+++ b/src/pl/plpgsql/src/expected/plpgsql_simple.out
@@ -0,0 +1,68 @@
+--
+-- Tests for plpgsql's handling of "simple" expressions
+--
+-- Check that changes to an inline-able function are handled correctly
+create function simplesql(int) returns int language sql
+as 'select $1';
+create function simplecaller() returns int language plpgsql
+as $$
+declare
+  sum int := 0;
+begin
+  for n in 1..10 loop
+    sum := sum + simplesql(n);
+    if n = 5 then
+      create or replace function simplesql(int) returns int language sql
+      as 'select $1 + 100';
+    end if;
+  end loop;
+  return sum;
+end$$;
+select simplecaller();
+ simplecaller 
+--------------
+          555
+(1 row)
+
+-- Check that changes in search path are dealt with correctly
+create schema simple1;
+create function simple1.simpletarget(int) returns int language plpgsql
+as $$begin return $1; end$$;
+create function simpletarget(int) returns int language plpgsql
+as $$begin return $1 + 100; end$$;
+create or replace function simplecaller() returns int language plpgsql
+as $$
+declare
+  sum int := 0;
+begin
+  for n in 1..10 loop
+    sum := sum + simpletarget(n);
+    if n = 5 then
+      set local search_path = 'simple1';
+    end if;
+  end loop;
+  return sum;
+end$$;
+select simplecaller();
+ simplecaller 
+--------------
+          555
+(1 row)
+
+-- try it with non-volatile functions, too
+alter function simple1.simpletarget(int) immutable;
+alter function simpletarget(int) immutable;
+select simplecaller();
+ simplecaller 
+--------------
+          555
+(1 row)
+
+-- make sure flushing local caches changes nothing
+\c -
+select simplecaller();
+ simplecaller 
+--------------
+          555
+(1 row)
+
diff --git a/src/pl/plpgsql/src/sql/plpgsql_simple.sql b/src/pl/plpgsql/src/sql/plpgsql_simple.sql
new file mode 100644
index 0000000..8a95768
--- /dev/null
+++ b/src/pl/plpgsql/src/sql/plpgsql_simple.sql
@@ -0,0 +1,61 @@
+--
+-- Tests for plpgsql's handling of "simple" expressions
+--
+
+-- Check that changes to an inline-able function are handled correctly
+create function simplesql(int) returns int language sql
+as 'select $1';
+
+create function simplecaller() returns int language plpgsql
+as $$
+declare
+  sum int := 0;
+begin
+  for n in 1..10 loop
+    sum := sum + simplesql(n);
+    if n = 5 then
+      create or replace function simplesql(int) returns int language sql
+      as 'select $1 + 100';
+    end if;
+  end loop;
+  return sum;
+end$$;
+
+select simplecaller();
+
+
+-- Check that changes in search path are dealt with correctly
+create schema simple1;
+
+create function simple1.simpletarget(int) returns int language plpgsql
+as $$begin return $1; end$$;
+
+create function simpletarget(int) returns int language plpgsql
+as $$begin return $1 + 100; end$$;
+
+create or replace function simplecaller() returns int language plpgsql
+as $$
+declare
+  sum int := 0;
+begin
+  for n in 1..10 loop
+    sum := sum + simpletarget(n);
+    if n = 5 then
+      set local search_path = 'simple1';
+    end if;
+  end loop;
+  return sum;
+end$$;
+
+select simplecaller();
+
+-- try it with non-volatile functions, too
+alter function simple1.simpletarget(int) immutable;
+alter function simpletarget(int) immutable;
+
+select simplecaller();
+
+-- make sure flushing local caches changes nothing
+\c -
+
+select simplecaller();