diff --git a/c/mapping/lrec_evaluators.c b/c/mapping/lrec_evaluators.c
index 60d8283dd..5f0b33da0 100644
--- a/c/mapping/lrec_evaluators.c
+++ b/c/mapping/lrec_evaluators.c
@@ -816,8 +816,8 @@ static function_lookup_t FUNCTION_LOOKUP_TABLE[] = {
 	{ FUNC_CLASS_MATH, "%",       2 , "Remainder; never negative-valued."},
 	{ FUNC_CLASS_MATH, "**",      2 , "Exponentiation; same as pow."},
 
-	{ FUNC_CLASS_BOOLEAN, "=~",      2 , "String (left-hand side) matches regex (right-hand side) [under construction]."},
-	{ FUNC_CLASS_BOOLEAN, "!=~",     2 , "String (left-hand side) does not match regex (right-hand side) [under construction]."},
+	{ FUNC_CLASS_BOOLEAN, "=~",      2 , "String (left-hand side) matches regex (right-hand side), e.g. '$name =~ \"^a.*b$\"'."},
+	{ FUNC_CLASS_BOOLEAN, "!=~",     2 , "String (left-hand side) does not match regex (right-hand side), e.g. '$name !=~ \"^a.*b$\"'."},
 	{ FUNC_CLASS_BOOLEAN, "==",      2 , "String/numeric equality. Mixing number and string results in string compare."},
 	{ FUNC_CLASS_BOOLEAN, "!=",      2 , "String/numeric inequality. Mixing number and string results in string compare."},
 	{ FUNC_CLASS_BOOLEAN, ">",       2 , "String/numeric greater-than. Mixing number and string results in string compare."},
diff --git a/c/reg_test/expected/out b/c/reg_test/expected/out
index fc3e61d5a..611540753 100644
--- a/c/reg_test/expected/out
+++ b/c/reg_test/expected/out
@@ -1490,6 +1490,46 @@ mlr filter -v $x<$a*$b+-$c /dev/null
         - (operator):
             c (field_name).
 
+mlr filter -v $x =~ "bcd" ./reg_test/input/regex.dkvp
+=~ (operator):
+    x (field_name).
+    bcd (literal).
+x=abcd,y=ghi
+x=abcde,y=ghi
+
+mlr filter -v $x =~ "^bcd" ./reg_test/input/regex.dkvp
+=~ (operator):
+    x (field_name).
+    ^bcd (literal).
+
+mlr filter -v $x =~ "^abc" ./reg_test/input/regex.dkvp
+=~ (operator):
+    x (field_name).
+    ^abc (literal).
+x=abc,y=def
+x=abcd,y=ghi
+x=abcde,y=ghi
+
+mlr filter -v $x =~ "^abc$" ./reg_test/input/regex.dkvp
+=~ (operator):
+    x (field_name).
+    ^abc$ (literal).
+x=abc,y=def
+
+mlr filter -v $x =~ "^a.*d$" ./reg_test/input/regex.dkvp
+=~ (operator):
+    x (field_name).
+    ^a.*d$ (literal).
+x=abcd,y=ghi
+
+mlr filter -v $x =~ "^a.*"."d$" ./reg_test/input/regex.dkvp
+=~ (operator):
+    x (field_name).
+    . (operator):
+        ^a.* (literal).
+        d$ (literal).
+x=abcd,y=ghi
+
 mlr --csvlite put $gmt=sec2gmt($sec) ./reg_test/input/sec2gmt
 sec,gmt
 0,1970-01-01T00:00:00Z
diff --git a/c/reg_test/input/regex.dkvp b/c/reg_test/input/regex.dkvp
new file mode 100644
index 000000000..2dab66388
--- /dev/null
+++ b/c/reg_test/input/regex.dkvp
@@ -0,0 +1,3 @@
+x=abc,y=def
+x=abcd,y=ghi
+x=abcde,y=ghi
diff --git a/c/reg_test/run b/c/reg_test/run
index fd636f9ec..47384c2be 100755
--- a/c/reg_test/run
+++ b/c/reg_test/run
@@ -308,6 +308,13 @@ run_mlr filter -v '$x<$a*-$b+$c'  /dev/null
 run_mlr filter -v '$x<$a+$b*-$c'  /dev/null
 run_mlr filter -v '$x<$a*$b+-$c'  /dev/null
 
+run_mlr filter -v '$x =~ "bcd"'       $indir/regex.dkvp
+run_mlr filter -v '$x =~ "^bcd"'      $indir/regex.dkvp
+run_mlr filter -v '$x =~ "^abc"'      $indir/regex.dkvp
+run_mlr filter -v '$x =~ "^abc$"'     $indir/regex.dkvp
+run_mlr filter -v '$x =~ "^a.*d$"'    $indir/regex.dkvp
+run_mlr filter -v '$x =~ "^a.*"."d$"' $indir/regex.dkvp
+
 run_mlr --csvlite put '$gmt=sec2gmt($sec)' $indir/sec2gmt
 run_mlr --csvlite put '$sec=gmt2sec($gmt)' $indir/gmt2sec