diff --git a/doc/usage.md b/doc/usage.md
index 5eaf9666..eff61087 100644
--- a/doc/usage.md
+++ b/doc/usage.md
@@ -250,7 +250,6 @@ fq can be used as a scrip interpreter:
 - [gojq's differences to jq](https://github.com/itchyny/gojq#difference-to-jq),
 notable is support for arbitrary-precision integers.
 - Supports hexdecimal `0xab`, octal `0o77` and binary `0b101` integer literals.
-- Has bitwise operators, `band`, `bor`, `bxor`, `bsl`, `bsr`, `bnot`.
 - Try include `include "file?";` that don't fail if file is missing.
 - Some values can act as a object with keys even when it's an array, number etc.
 - There can be keys hidden from `keys` and `[]`.
@@ -269,6 +268,8 @@ notable is support for arbitrary-precision integers.
   - `diff/2` produce diff object between two values.
   - `delta/0`, `delta_by/1`, array with difference between all consecutive pairs.
   - `chunk/1`, split array or string into even chunks
+- Bitwise functions `band`, `bor`, `bxor`, `bsl`, `bsr` and `bnot`. Works the same as jq math functions,
+unary uses input and if more than one argument all as arguments ignoring the input. Ex: `1 | bnot` `bsl(1; 3)`
 - Adds some decode value specific functions:
   - `root/0` tree root for value
   - `buffer_root/0` root value of buffer for value
diff --git a/pkg/interp/testdata/bitops.fqtest b/pkg/interp/testdata/bitops.fqtest
index b5a97e49..8f3b93c0 100644
--- a/pkg/interp/testdata/bitops.fqtest
+++ b/pkg/interp/testdata/bitops.fqtest
@@ -4,24 +4,48 @@ null> 0, -1, 1208925819614629174706175, -1208925819614629174706176 | bnot
 0
 -1208925819614629174706176
 1208925819614629174706175
+null> null | bnot
+error: cannot bnot: null
+null> bnot(1)
+error: repl:1:0: function not defined: bnot/1
 null> [0,0], [8,1], [0xffff_ffff_ffff_ffff,1] | bsl(.[0]; .[1])
 0
 16
 36893488147419103230
+null> bsl(1)
+error: repl:1:0: function not defined: bsl/1
+null> bsl(null; 1)
+error: cannot bsl: null and number
 null> [0,0], [8,1], [0x1_ffff_ffff_ffff_fffe,1] | bsr(.[0]; .[1])
 0
 4
 18446744073709551615
+null> bsr(1)
+error: repl:1:0: function not defined: bsr/1
+null> bsr(null; 1)
+error: cannot bsr: null and number
 null> [0,0], [0xffff_ffff_ffff_ffff_ffff,0x1234], [0x1234,0xffff_ffff_ffff_ffff_ffff,0x1234] | band(.[0]; .[1])
 0
 4660
 4660
+null> band(1)
+error: repl:1:0: function not defined: band/1
+null> band(null; 1)
+error: cannot band: null and number
 null> [0,0], [0xffff_ffff_ffff_ffff_0000,0x1234], [0x1234,0xffff_ffff_ffff_ffff_0000,0x1234] | bor(.[0]; .[1])
 0
 1208925819614629174645300
 1208925819614629174645300
+null> bor(1)
+error: repl:1:0: function not defined: bor/1
+null> bor(null; 1)
+error: cannot bor: null and number
 null> [0,0], [0xffff_ffff_ffff_ffff_ffff,0x1234], [0x1234,0xffff_ffff_ffff_ffff_ffff,0x1234] | bxor(.[0]; .[1])
 0
 1208925819614629174701515
 1208925819614629174701515
+null> bxor(1)
+error: repl:1:0: function not defined: bxor/1
+null> bxor(null; 1)
+error: cannot bxor: null and number
 null> ^D