diff --git a/src/test/modules/test_regex/expected/test_regex.out b/src/test/modules/test_regex/expected/test_regex.out
index 611b6c7243..6242d0baa9 100644
--- a/src/test/modules/test_regex/expected/test_regex.out
+++ b/src/test/modules/test_regex/expected/test_regex.out
@@ -937,6 +937,34 @@ select * from test_regex('a[[=x=]]', 'az', '+Lb');
  {0,REG_ULOCALE}
 (1 row)
 
+-- expectMatch	9.9b  &iL	{a[[=Y=]]}	ay	ay
+select * from test_regex('a[[=Y=]]', 'ay', 'iL');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+ {ay}
+(2 rows)
+
+select * from test_regex('a[[=Y=]]', 'ay', 'iLb');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+ {ay}
+(2 rows)
+
+-- expectNomatch	9.9c  &L	{a[[=Y=]]}	ay
+select * from test_regex('a[[=Y=]]', 'ay', 'L');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+(1 row)
+
+select * from test_regex('a[[=Y=]]', 'ay', 'Lb');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+(1 row)
+
 -- expectError	9.10 &		{a[0-[=x=]]}	ERANGE
 select * from test_regex('a[0-[=x=]]', '', '');
 ERROR:  invalid regular expression: invalid character range
@@ -2932,6 +2960,34 @@ select * from test_regex('a[^b-d]', 'aC', 'iMb');
  {0,REG_UUNPORT}
 (1 row)
 
+-- expectMatch	19.6 &iM	{a[B-Z]}	aC	aC
+select * from test_regex('a[B-Z]', 'aC', 'iM');
+   test_regex    
+-----------------
+ {0,REG_UUNPORT}
+ {aC}
+(2 rows)
+
+select * from test_regex('a[B-Z]', 'aC', 'iMb');
+   test_regex    
+-----------------
+ {0,REG_UUNPORT}
+ {aC}
+(2 rows)
+
+-- expectNomatch	19.7 &iM	{a[^B-Z]}	aC
+select * from test_regex('a[^B-Z]', 'aC', 'iM');
+   test_regex    
+-----------------
+ {0,REG_UUNPORT}
+(1 row)
+
+select * from test_regex('a[^B-Z]', 'aC', 'iMb');
+   test_regex    
+-----------------
+ {0,REG_UUNPORT}
+(1 row)
+
 -- doing 20 "directors and embedded options"
 -- expectError	20.1  &		***?		BADPAT
 select * from test_regex('***?', '', '');
@@ -3850,6 +3906,14 @@ select * from test_regex('^([^/]+?)(?:/([^/]+?))(?:/([^/]+?))?$', 'foo/bar/baz',
  {foo/bar/baz,foo,bar,baz}
 (2 rows)
 
+-- expectMatch	24.14 PRT	{^(.+?)(?:/(.+?))(?:/(.+?)\3)?$}	{foo/bar/baz/quux}	{foo/bar/baz/quux}	{foo}	{bar/baz/quux}	{}
+select * from test_regex('^(.+?)(?:/(.+?))(?:/(.+?)\3)?$', 'foo/bar/baz/quux', 'PRT');
+                  test_regex                  
+----------------------------------------------
+ {3,REG_UBACKREF,REG_UNONPOSIX,REG_USHORTEST}
+ {foo/bar/baz/quux,foo,bar/baz/quux,NULL}
+(2 rows)
+
 -- doing 25 "mixed quantifiers"
 -- # this is very incomplete as yet
 -- # should include |
diff --git a/src/test/modules/test_regex/expected/test_regex_utf8.out b/src/test/modules/test_regex/expected/test_regex_utf8.out
index 112698ac61..3b56f36c07 100644
--- a/src/test/modules/test_regex/expected/test_regex_utf8.out
+++ b/src/test/modules/test_regex/expected/test_regex_utf8.out
@@ -98,3 +98,109 @@ select * from test_regex('[[:alnum:]]*[[:upper:]]*[\u1000-\u2000]*\u1237',
  {0,REG_UBBS,REG_UNONPOSIX,REG_UUNPORT,REG_ULOCALE}
 (1 row)
 
+select * from test_regex('[[:alnum:]]*[[:upper:]]*[\u1000-\u2000]*\u1237',
+  E'\u1500\u1237', 'iELMP');
+                     test_regex                     
+----------------------------------------------------
+ {0,REG_UBBS,REG_UNONPOSIX,REG_UUNPORT,REG_ULOCALE}
+ {ᔀሷ}
+(2 rows)
+
+-- systematically test char classes
+select * from test_regex('[[:alnum:]]+',  E'x\u1500\u1237', 'L');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+ {xᔀሷ}
+(2 rows)
+
+select * from test_regex('[[:alpha:]]+',  E'x\u1500\u1237', 'L');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+ {xᔀሷ}
+(2 rows)
+
+select * from test_regex('[[:ascii:]]+',  E'x\u1500\u1237', 'L');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+ {x}
+(2 rows)
+
+select * from test_regex('[[:blank:]]+',  E'x \t\u1500\u1237', 'L');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+ {"      "}
+(2 rows)
+
+select * from test_regex('[[:cntrl:]]+',  E'x\u1500\u1237', 'L');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+(1 row)
+
+select * from test_regex('[[:digit:]]+',  E'x9\u1500\u1237', 'L');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+ {9}
+(2 rows)
+
+select * from test_regex('[[:graph:]]+',  E'x\u1500\u1237', 'L');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+ {xᔀሷ}
+(2 rows)
+
+select * from test_regex('[[:lower:]]+',  E'x\u1500\u1237', 'L');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+ {x}
+(2 rows)
+
+select * from test_regex('[[:print:]]+',  E'x\u1500\u1237', 'L');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+ {xᔀሷ}
+(2 rows)
+
+select * from test_regex('[[:punct:]]+',  E'x.\u1500\u1237', 'L');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+ {.}
+(2 rows)
+
+select * from test_regex('[[:space:]]+',  E'x \t\u1500\u1237', 'L');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+ {"      "}
+(2 rows)
+
+select * from test_regex('[[:upper:]]+',  E'xX\u1500\u1237', 'L');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+ {X}
+(2 rows)
+
+select * from test_regex('[[:xdigit:]]+',  E'xa9\u1500\u1237', 'L');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+ {a9}
+(2 rows)
+
+select * from test_regex('[[:word:]]+',  E'x_\u1500\u1237', 'L');
+   test_regex    
+-----------------
+ {0,REG_ULOCALE}
+ {x_ᔀሷ}
+(2 rows)
+
diff --git a/src/test/modules/test_regex/sql/test_regex.sql b/src/test/modules/test_regex/sql/test_regex.sql
index 13a0586272..389b8b61b3 100644
--- a/src/test/modules/test_regex/sql/test_regex.sql
+++ b/src/test/modules/test_regex/sql/test_regex.sql
@@ -304,6 +304,12 @@ select * from test_regex('a[[=x=]]', 'ay', '+Lb');
 -- expectNomatch	9.9  &+L	{a[[=x=]]}	az
 select * from test_regex('a[[=x=]]', 'az', '+L');
 select * from test_regex('a[[=x=]]', 'az', '+Lb');
+-- expectMatch	9.9b  &iL	{a[[=Y=]]}	ay	ay
+select * from test_regex('a[[=Y=]]', 'ay', 'iL');
+select * from test_regex('a[[=Y=]]', 'ay', 'iLb');
+-- expectNomatch	9.9c  &L	{a[[=Y=]]}	ay
+select * from test_regex('a[[=Y=]]', 'ay', 'L');
+select * from test_regex('a[[=Y=]]', 'ay', 'Lb');
 -- expectError	9.10 &		{a[0-[=x=]]}	ERANGE
 select * from test_regex('a[0-[=x=]]', '', '');
 select * from test_regex('a[0-[=x=]]', '', 'b');
@@ -864,6 +870,12 @@ select * from test_regex('a[b-d]', 'aC', 'iMb');
 -- expectNomatch	19.5 &iM	{a[^b-d]}	aC
 select * from test_regex('a[^b-d]', 'aC', 'iM');
 select * from test_regex('a[^b-d]', 'aC', 'iMb');
+-- expectMatch	19.6 &iM	{a[B-Z]}	aC	aC
+select * from test_regex('a[B-Z]', 'aC', 'iM');
+select * from test_regex('a[B-Z]', 'aC', 'iMb');
+-- expectNomatch	19.7 &iM	{a[^B-Z]}	aC
+select * from test_regex('a[^B-Z]', 'aC', 'iM');
+select * from test_regex('a[^B-Z]', 'aC', 'iMb');
 
 -- doing 20 "directors and embedded options"
 
@@ -1171,6 +1183,8 @@ select * from test_regex('z*4', '123zzzz456', '-');
 select * from test_regex('z*?4', '123zzzz456', 'PT');
 -- expectMatch	24.13 PT	{^([^/]+?)(?:/([^/]+?))(?:/([^/]+?))?$}	{foo/bar/baz}	{foo/bar/baz} {foo} {bar} {baz}
 select * from test_regex('^([^/]+?)(?:/([^/]+?))(?:/([^/]+?))?$', 'foo/bar/baz', 'PT');
+-- expectMatch	24.14 PRT	{^(.+?)(?:/(.+?))(?:/(.+?)\3)?$}	{foo/bar/baz/quux}	{foo/bar/baz/quux}	{foo}	{bar/baz/quux}	{}
+select * from test_regex('^(.+?)(?:/(.+?))(?:/(.+?)\3)?$', 'foo/bar/baz/quux', 'PRT');
 
 -- doing 25 "mixed quantifiers"
 -- # this is very incomplete as yet
diff --git a/src/test/modules/test_regex/sql/test_regex_utf8.sql b/src/test/modules/test_regex/sql/test_regex_utf8.sql
index cfd9396194..f23907162e 100644
--- a/src/test/modules/test_regex/sql/test_regex_utf8.sql
+++ b/src/test/modules/test_regex/sql/test_regex_utf8.sql
@@ -58,3 +58,21 @@ select * from test_regex('[[:alnum:]]*[[:upper:]]*[\u1000-\u2000]*\u1237',
   E'\u1500\u1237', 'ELMP');
 select * from test_regex('[[:alnum:]]*[[:upper:]]*[\u1000-\u2000]*\u1237',
   E'A\u1239', 'ELMP');
+select * from test_regex('[[:alnum:]]*[[:upper:]]*[\u1000-\u2000]*\u1237',
+  E'\u1500\u1237', 'iELMP');
+
+-- systematically test char classes
+select * from test_regex('[[:alnum:]]+',  E'x\u1500\u1237', 'L');
+select * from test_regex('[[:alpha:]]+',  E'x\u1500\u1237', 'L');
+select * from test_regex('[[:ascii:]]+',  E'x\u1500\u1237', 'L');
+select * from test_regex('[[:blank:]]+',  E'x \t\u1500\u1237', 'L');
+select * from test_regex('[[:cntrl:]]+',  E'x\u1500\u1237', 'L');
+select * from test_regex('[[:digit:]]+',  E'x9\u1500\u1237', 'L');
+select * from test_regex('[[:graph:]]+',  E'x\u1500\u1237', 'L');
+select * from test_regex('[[:lower:]]+',  E'x\u1500\u1237', 'L');
+select * from test_regex('[[:print:]]+',  E'x\u1500\u1237', 'L');
+select * from test_regex('[[:punct:]]+',  E'x.\u1500\u1237', 'L');
+select * from test_regex('[[:space:]]+',  E'x \t\u1500\u1237', 'L');
+select * from test_regex('[[:upper:]]+',  E'xX\u1500\u1237', 'L');
+select * from test_regex('[[:xdigit:]]+',  E'xa9\u1500\u1237', 'L');
+select * from test_regex('[[:word:]]+',  E'x_\u1500\u1237', 'L');