diff --git a/lib/diagnostic.js b/lib/diagnostic.js
index 776b96c..ca1dc98 100644
--- a/lib/diagnostic.js
+++ b/lib/diagnostic.js
@@ -47,9 +47,16 @@ function * tokensToDiagnostic (inp, width = 100) {
       case 'bytes':
       case 'map':
       case 'array':
-        // for bytes and string, we want to print out the length part of the value prefix if it
-        // exists - it exists for short lengths (<24) but does for longer lengths
-        multilen = token.type.name === 'string' ? utf8Encoder.encode(token.value).length : token.value.length
+        // print the length bytes if they exist (length >= 24)
+        // for string/bytes, token.value is the content; for array/map, token.value IS the count
+        if (token.type.name === 'string') {
+          multilen = utf8Encoder.encode(token.value).length
+        } else if (token.type.name === 'bytes') {
+          multilen = token.value.length
+        } else {
+          // array or map - value is the count directly
+          multilen = token.value
+        }
         if (multilen >= uintBoundaries[0]) {
           if (multilen < uintBoundaries[1]) {
             outp += ` ${slc(1, 1)}`
diff --git a/package.json b/package.json
index 571605b..64e730c 100644
--- a/package.json
+++ b/package.json
@@ -13,8 +13,9 @@
     "build:types": "tsc --build",
     "prepublishOnly": "npm run build",
     "test:node": "c8 --check-coverage --exclude=test/** mocha test/test-*.js",
+    "test:node-bin": "mocha test/node-test-bin.js",
     "test:browser": "polendina --cleanup test/test-*.js",
-    "test": "npm run lint && npm run build && npm run test:node && npm run test:browser",
+    "test": "npm run lint && npm run build && npm run test:node && npm run test:node-bin && npm run test:browser",
     "test:ci": "npm run test",
     "coverage": "c8 --reporter=html --reporter=text mocha test/test-*.js && npx st -d coverage -p 8888"
   },
diff --git a/test/node-test-bin.js b/test/node-test-bin.js
index fa558a3..6c9f889 100644
--- a/test/node-test-bin.js
+++ b/test/node-test-bin.js
@@ -97,17 +97,17 @@ describe('Bin', () => {
       assert.strictEqual(e.stderr,
 `Usage: cborg <command> <args>
 Valid commands:
-\tbin2diag [binary input]
+\tbin2diag [--width <width>] [binary input]
 \tbin2hex [binary input]
 \tbin2json [--pretty] [binary input]
 \tdiag2bin [diagnostic input]
 \tdiag2hex [diagnostic input]
 \tdiag2json [--pretty] [diagnostic input]
 \thex2bin [hex input]
-\thex2diag [hex input]
+\thex2diag [--width <width>] [hex input]
 \thex2json [--pretty] [hex input]
 \tjson2bin '[json input]'
-\tjson2diag '[json input]'
+\tjson2diag [--width <width>] '[json input]'
 \tjson2hex '[json input]'
 Input may either be supplied as an argument or piped via stdin
 `)
@@ -124,17 +124,17 @@ Input may either be supplied as an argument or piped via stdin
 `Unknown command: 'blip'
 Usage: cborg <command> <args>
 Valid commands:
-\tbin2diag [binary input]
+\tbin2diag [--width <width>] [binary input]
 \tbin2hex [binary input]
 \tbin2json [--pretty] [binary input]
 \tdiag2bin [diagnostic input]
 \tdiag2hex [diagnostic input]
 \tdiag2json [--pretty] [diagnostic input]
 \thex2bin [hex input]
-\thex2diag [hex input]
+\thex2diag [--width <width>] [hex input]
 \thex2json [--pretty] [hex input]
 \tjson2bin '[json input]'
-\tjson2diag '[json input]'
+\tjson2diag [--width <width>] '[json input]'
 \tjson2hex '[json input]'
 Input may either be supplied as an argument or piped via stdin
 `)
@@ -147,17 +147,17 @@ Input may either be supplied as an argument or piped via stdin
     assert.strictEqual(stderr,
 `Usage: cborg <command> <args>
 Valid commands:
-\tbin2diag [binary input]
+\tbin2diag [--width <width>] [binary input]
 \tbin2hex [binary input]
 \tbin2json [--pretty] [binary input]
 \tdiag2bin [diagnostic input]
 \tdiag2hex [diagnostic input]
 \tdiag2json [--pretty] [diagnostic input]
 \thex2bin [hex input]
-\thex2diag [hex input]
+\thex2diag [--width <width>] [hex input]
 \thex2json [--pretty] [hex input]
 \tjson2bin '[json input]'
-\tjson2diag '[json input]'
+\tjson2diag [--width <width>] '[json input]'
 \tjson2hex '[json input]'
 Input may either be supplied as an argument or piped via stdin
 `)
@@ -341,6 +341,23 @@ Input may either be supplied as an argument or piped via stdin
   })
 
   describe('diag length bytes', () => {
+    // issue #137 - array and map length bytes were missing for lengths >= 24
+    it('array with 24 elements', async () => {
+      // 98 18 = array(24), then 24 uint(1) values
+      const hex = '9818' + '01'.repeat(24)
+      const { stdout, stderr } = await execBin(`hex2diag ${hex}`)
+      assert.strictEqual(stderr, '')
+      assert.ok(stdout.startsWith('98 18                                             # array(24)\n'))
+    })
+
+    it('map with 24 entries', async () => {
+      // b8 18 = map(24), then 24 pairs of string('a')=uint(1)
+      const hex = 'b818' + '616101'.repeat(24)
+      const { stdout, stderr } = await execBin(`hex2diag ${hex}`)
+      assert.strictEqual(stderr, '')
+      assert.ok(stdout.startsWith('b8 18                                             # map(24)\n'))
+    })
+
     it('compact', async () => {
       const { stdout, stderr } = await execBin('json2diag', '"aaaaaaaaaaaaaaaaaaaaaaa"')
       assert.strictEqual(stderr, '')
diff --git a/types/lib/byte-utils.d.ts.map b/types/lib/byte-utils.d.ts.map
index 4fb60af..ca012ab 100644
--- a/types/lib/byte-utils.d.ts.map
+++ b/types/lib/byte-utils.d.ts.map
@@ -1 +1 @@
-{"version":3,"file":"byte-utils.d.ts","sourceRoot":"","sources":["../../lib/byte-utils.js"],"names":[],"mappings":"AAuBA;;;GAGG;AACH,2BAHW,UAAU,GAAC,MAAM,EAAE,GACjB,UAAU,CAQtB;AAoMD;;;;GAIG;AACH,4BAJW,UAAU,MACV,UAAU,GACR,MAAM,CAgBlB;AA6CD;;;GAGG;AACH,kDAHW,MAAM,EAAE,GACN,MAAM,CAkBlB;AArTD,gCAMkD;AAyBlD,mCAGe,MAAM,iDAYN,MAAM,6CAIhB;AAOE,+BAHI,MAAM,EAAE,GACN,UAAU,CAItB;AAIG;;;;GAIG;AAEH,6BALW,UAAU,SACV,MAAM,OACN,MAAM,2BAQhB;AAcD;;;;GAIG;AACH,+BAJW,UAAU,EAAE,UACZ,MAAM,GACJ,UAAU,CActB;AAwBD;;;GAGG;AACH,4BAHW,MAAM,GACJ,UAAU,CAMtB;AAaD;;;GAGG;AACH,yBAHW,UAAU,GACR,MAAM,CAQlB;AAiBH;;;GAGG;AACD,6BAHS,MAAM,GAAC,UAAU,GACf,UAAU,CAQpB"}
\ No newline at end of file
+{"version":3,"file":"byte-utils.d.ts","sourceRoot":"","sources":["../../lib/byte-utils.js"],"names":[],"mappings":"AAuBA;;;GAGG;AACH,2BAHW,UAAU,GAAC,MAAM,EAAE,GACjB,UAAU,CAQtB;AA0MD;;;;GAIG;AACH,4BAJW,UAAU,MACV,UAAU,GACR,MAAM,CAgBlB;AA6CD;;;GAGG;AACH,kDAHW,MAAM,EAAE,GACN,MAAM,CAkBlB;AA3TD,gCAMkD;AA+BlD,mCAGe,MAAM,iDAYN,MAAM,6CAIhB;AAOE,+BAHI,MAAM,EAAE,GACN,UAAU,CAItB;AAIG;;;;GAIG;AAEH,6BALW,UAAU,SACV,MAAM,OACN,MAAM,2BAQhB;AAcD;;;;GAIG;AACH,+BAJW,UAAU,EAAE,UACZ,MAAM,GACJ,UAAU,CActB;AAwBD;;;GAGG;AACH,4BAHW,MAAM,GACJ,UAAU,CAMtB;AAaD;;;GAGG;AACH,yBAHW,UAAU,GACR,MAAM,CAQlB;AAiBH;;;GAGG;AACD,6BAHS,MAAM,GAAC,UAAU,GACf,UAAU,CAQpB"}
\ No newline at end of file
diff --git a/types/lib/diagnostic.d.ts.map b/types/lib/diagnostic.d.ts.map
index 14c2985..625b750 100644
--- a/types/lib/diagnostic.d.ts.map
+++ b/types/lib/diagnostic.d.ts.map
@@ -1 +1 @@
-{"version":3,"file":"diagnostic.d.ts","sourceRoot":"","sources":["../../lib/diagnostic.js"],"names":[],"mappings":"AAOA;;;GAGG;AACH,wCAHW,UAAU,UACV,MAAM,oCA4HhB;AAED;;;;GAIG;AACH,gCAHW,MAAM,GACJ,UAAU,CAatB"}
\ No newline at end of file
+{"version":3,"file":"diagnostic.d.ts","sourceRoot":"","sources":["../../lib/diagnostic.js"],"names":[],"mappings":"AAOA;;;GAGG;AACH,wCAHW,UAAU,UACV,MAAM,oCAmIhB;AAED;;;;GAIG;AACH,gCAHW,MAAM,GACJ,UAAU,CAatB"}
\ No newline at end of file