diff --git a/cpp/ql/test/library-tests/regex/parse.expected b/cpp/ql/test/library-tests/regex/parse.expected
index 2ab6e455bd5..420e3f043ae 100644
--- a/cpp/ql/test/library-tests/regex/parse.expected
+++ b/cpp/ql/test/library-tests/regex/parse.expected
@@ -40,6 +40,32 @@
 
 #-----| [RegExpConstant, RegExpNormalChar] F
 
+#-----| [RegExpConstant, RegExpNormalChar] [
+
+#-----| [RegExpConstant, RegExpNormalChar] [
+
+#-----| [RegExpConstant, RegExpNormalChar] .
+
+#-----| [RegExpConstant, RegExpNormalChar] b
+
+#-----| [RegExpConstant, RegExpNormalChar] .
+
+#-----| [RegExpConstant, RegExpNormalChar] ]a-f]
+
+#-----| [RegExpConstant, RegExpNormalChar] [
+
+#-----| [RegExpConstant, RegExpNormalChar] .
+
+#-----| [RegExpConstant, RegExpNormalChar] a
+
+#-----| [RegExpConstant, RegExpNormalChar] .
+
+#-----| [RegExpConstant, RegExpNormalChar] ]
+
+#-----| [RegExpConstant, RegExpNormalChar] A
+
+#-----| [RegExpConstant, RegExpNormalChar] F
+
 #-----| [RegExpConstant, RegExpNormalChar] a
 
 #-----| [RegExpConstant, RegExpNormalChar] f
@@ -171,6 +197,14 @@
 #-----| 1 -> [RegExpConstant, RegExpEscape] \n
 #-----| 2 -> [RegExpConstant, RegExpNormalChar] b
 
+#-----| [RegExpSequence] [A-F[[.b.]]a-f]
+#-----| 0 -> [RegExpCharacterClass] [A-F[[.b.]
+#-----| 1 -> [RegExpConstant, RegExpNormalChar] ]a-f]
+
+#-----| [RegExpSequence] [[.a.]]
+#-----| 0 -> [RegExpCharacterClass] [[.a.]
+#-----| 1 -> [RegExpConstant, RegExpNormalChar] ]
+
 #-----| [RegExpSequence] [[:alpha:]][[:digit:]]
 #-----| 0 -> [RegExpCharacterClass] [[:alpha:]]
 #-----| 1 -> [RegExpCharacterClass] [[:digit:]]
@@ -263,6 +297,10 @@
 #-----| 0 -> [RegExpConstant, RegExpNormalChar] A
 #-----| 1 -> [RegExpConstant, RegExpNormalChar] F
 
+#-----| [RegExpCharacterRange] A-F
+#-----| 0 -> [RegExpConstant, RegExpNormalChar] A
+#-----| 1 -> [RegExpConstant, RegExpNormalChar] F
+
 #-----| [RegExpCharacterRange] a-f
 #-----| 0 -> [RegExpConstant, RegExpNormalChar] a
 #-----| 1 -> [RegExpConstant, RegExpNormalChar] f
@@ -293,6 +331,20 @@
 #-----| [RegExpCharacterClass] [\cZ]
 #-----| 0 -> [RegExpConstant, RegExpEscape] \cZ
 
+#-----| [RegExpCharacterClass] [A-F[[.b.]
+#-----| 0 -> [RegExpCharacterRange] A-F
+#-----| 1 -> [RegExpConstant, RegExpNormalChar] [
+#-----| 2 -> [RegExpConstant, RegExpNormalChar] [
+#-----| 3 -> [RegExpConstant, RegExpNormalChar] .
+#-----| 4 -> [RegExpConstant, RegExpNormalChar] b
+#-----| 5 -> [RegExpConstant, RegExpNormalChar] .
+
+#-----| [RegExpCharacterClass] [[.a.]
+#-----| 0 -> [RegExpConstant, RegExpNormalChar] [
+#-----| 1 -> [RegExpConstant, RegExpNormalChar] .
+#-----| 2 -> [RegExpConstant, RegExpNormalChar] a
+#-----| 3 -> [RegExpConstant, RegExpNormalChar] .
+
 #-----| [RegExpCharacterClass] [A-F[:digit:]a-f]
 #-----| 0 -> [RegExpCharacterRange] A-F
 
diff --git a/cpp/ql/test/library-tests/regex/regexp.cpp b/cpp/ql/test/library-tests/regex/regexp.cpp
index 18c3b8d3e48..ebf3b49367f 100644
--- a/cpp/ql/test/library-tests/regex/regexp.cpp
+++ b/cpp/ql/test/library-tests/regex/regexp.cpp
@@ -70,6 +70,10 @@ std::regex r_posix2("[[:alpha:][:digit:]]");
 // A single character class containing two ranges and one POSIX bracket expression
 std::regex r_posix3("[A-F[:digit:]a-f]");
 
+// POSIX collating symbols
+std::regex r_posix_coll1("[[.a.]]");
+std::regex r_posix_coll2("[A-F[[.b.]]a-f]");
+
 // *Not* a POSIX bracket expression; just a regular character class.
 std::regex r_posix4("[:digit:]");
 
diff --git a/cpp/ql/test/library-tests/regex/regexp.expected b/cpp/ql/test/library-tests/regex/regexp.expected
index f8bb2b9b726..18707fb6a52 100644
--- a/cpp/ql/test/library-tests/regex/regexp.expected
+++ b/cpp/ql/test/library-tests/regex/regexp.expected
@@ -23,6 +23,10 @@ term
 | file://:0:0:0:0 | (foo)*bar | RegExpSequence |
 | file://:0:0:0:0 | (o\|b) | RegExpGroup |
 | file://:0:0:0:0 | - | RegExpConstant,RegExpNormalChar |
+| file://:0:0:0:0 | . | RegExpConstant,RegExpNormalChar |
+| file://:0:0:0:0 | . | RegExpConstant,RegExpNormalChar |
+| file://:0:0:0:0 | . | RegExpConstant,RegExpNormalChar |
+| file://:0:0:0:0 | . | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | . | RegExpDot |
 | file://:0:0:0:0 | . | RegExpDot |
 | file://:0:0:0:0 | .* | RegExpStar |
@@ -32,16 +36,26 @@ term
 | file://:0:0:0:0 | A | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | A | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | A | RegExpConstant,RegExpNormalChar |
+| file://:0:0:0:0 | A | RegExpConstant,RegExpNormalChar |
+| file://:0:0:0:0 | A-F | RegExpCharacterRange |
 | file://:0:0:0:0 | A-F | RegExpCharacterRange |
 | file://:0:0:0:0 | A-F | RegExpCharacterRange |
 | file://:0:0:0:0 | A-F] | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | A-Z | RegExpCharacterRange |
 | file://:0:0:0:0 | F | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | F | RegExpConstant,RegExpNormalChar |
+| file://:0:0:0:0 | F | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | Z | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | [ | RegExpConstant,RegExpNormalChar |
+| file://:0:0:0:0 | [ | RegExpConstant,RegExpNormalChar |
+| file://:0:0:0:0 | [ | RegExpConstant,RegExpNormalChar |
+| file://:0:0:0:0 | [ | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | [123] | RegExpCharacterClass |
 | file://:0:0:0:0 | [A-F[:digit:]a-f] | RegExpCharacterClass |
+| file://:0:0:0:0 | [A-F[[.b.] | RegExpCharacterClass |
+| file://:0:0:0:0 | [A-F[[.b.]]a-f] | RegExpSequence |
+| file://:0:0:0:0 | [[.a.] | RegExpCharacterClass |
+| file://:0:0:0:0 | [[.a.]] | RegExpSequence |
 | file://:0:0:0:0 | [[:alpha:][:digit:]] | RegExpCharacterClass |
 | file://:0:0:0:0 | [[:alpha:]] | RegExpCharacterClass |
 | file://:0:0:0:0 | [[:alpha:]][[:digit:]] | RegExpSequence |
@@ -91,6 +105,8 @@ term
 | file://:0:0:0:0 | \| | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | ] | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | ] | RegExpConstant,RegExpNormalChar |
+| file://:0:0:0:0 | ] | RegExpConstant,RegExpNormalChar |
+| file://:0:0:0:0 | ]a-f] | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | _ | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | a | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | a | RegExpConstant,RegExpNormalChar |
@@ -104,6 +120,7 @@ term
 | file://:0:0:0:0 | a | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | a | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | a | RegExpConstant,RegExpNormalChar |
+| file://:0:0:0:0 | a | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | a* | RegExpStar |
 | file://:0:0:0:0 | a*b+c?d | RegExpSequence |
 | file://:0:0:0:0 | a+ | RegExpPlus |
@@ -135,6 +152,7 @@ term
 | file://:0:0:0:0 | b | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | b | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | b | RegExpConstant,RegExpNormalChar |
+| file://:0:0:0:0 | b | RegExpConstant,RegExpNormalChar |
 | file://:0:0:0:0 | b+ | RegExpPlus |
 | file://:0:0:0:0 | b+ | RegExpPlus |
 | file://:0:0:0:0 | bar | RegExpConstant,RegExpNormalChar |
@@ -163,15 +181,24 @@ regExpNormalCharValue
 | file://:0:0:0:0 | 9 | 9 |
 | file://:0:0:0:0 | !a | !a |
 | file://:0:0:0:0 | - | - |
+| file://:0:0:0:0 | . | . |
+| file://:0:0:0:0 | . | . |
+| file://:0:0:0:0 | . | . |
+| file://:0:0:0:0 | . | . |
 | file://:0:0:0:0 | : | : |
 | file://:0:0:0:0 | A | A |
 | file://:0:0:0:0 | A | A |
 | file://:0:0:0:0 | A | A |
+| file://:0:0:0:0 | A | A |
 | file://:0:0:0:0 | A-F] | A-F] |
 | file://:0:0:0:0 | F | F |
 | file://:0:0:0:0 | F | F |
+| file://:0:0:0:0 | F | F |
 | file://:0:0:0:0 | Z | Z |
 | file://:0:0:0:0 | [ | [ |
+| file://:0:0:0:0 | [ | [ |
+| file://:0:0:0:0 | [ | [ |
+| file://:0:0:0:0 | [ | [ |
 | file://:0:0:0:0 | \\0 | 0 |
 | file://:0:0:0:0 | \\0 | 0 |
 | file://:0:0:0:0 | \\D | D |
@@ -194,6 +221,8 @@ regExpNormalCharValue
 | file://:0:0:0:0 | \| | \| |
 | file://:0:0:0:0 | ] | ] |
 | file://:0:0:0:0 | ] | ] |
+| file://:0:0:0:0 | ] | ] |
+| file://:0:0:0:0 | ]a-f] | ]a-f] |
 | file://:0:0:0:0 | _ | _ |
 | file://:0:0:0:0 | a | a |
 | file://:0:0:0:0 | a | a |
@@ -207,6 +236,7 @@ regExpNormalCharValue
 | file://:0:0:0:0 | a | a |
 | file://:0:0:0:0 | a | a |
 | file://:0:0:0:0 | a | a |
+| file://:0:0:0:0 | a | a |
 | file://:0:0:0:0 | abc | abc |
 | file://:0:0:0:0 | abc | abc |
 | file://:0:0:0:0 | abc | abc |
@@ -226,6 +256,7 @@ regExpNormalCharValue
 | file://:0:0:0:0 | b | b |
 | file://:0:0:0:0 | b | b |
 | file://:0:0:0:0 | b | b |
+| file://:0:0:0:0 | b | b |
 | file://:0:0:0:0 | bar | bar |
 | file://:0:0:0:0 | bar | bar |
 | file://:0:0:0:0 | c | c |