diff --git a/bin/jskos-convert b/bin/jskos-convert
index a803d86..aa1cf0e 100755
--- a/bin/jskos-convert
+++ b/bin/jskos-convert
@@ -18,6 +18,7 @@ program
   .option("-m, --marktop", "explicitly mark concepts without broader as top concepts")
   .option("--creator <uri and/or name>", "add creator to mappings")
   .option("--created <timestamp>", "add creation timestamp to mappings")
+  .option("-i, --identifier", "add mapping sameness identifier")
   .option("--delimiter <char>", "CSV delimiter (default: ,)")
   .example("mappings -t csv mappings.ndjson")
   .example("concepts -r registry.json -s example http://example.org/jskos.csv")
diff --git a/lib/jskos-convert.js b/lib/jskos-convert.js
index 9cee87d..897464e 100644
--- a/lib/jskos-convert.js
+++ b/lib/jskos-convert.js
@@ -11,7 +11,7 @@ import mappingsFromRows from "./csv-to-mapping.js"
 import conceptsFromRows from "./csv-to-concept.js"
 import rowsFromConcepts from "./concept-to-csv.js"
 
-import { ConceptScheme } from "jskos-tools"
+import { ConceptScheme, addMappingIdentifiers } from "jskos-tools"
 
 import rdfSerializer from "./rdf-serializer.js"
 import { formats } from "./rdf-serializer.js"
@@ -86,6 +86,18 @@ function convert (opts) {
     } else if (from === "csv" && to === "ndjson") {
       steps.push(mappingsFromRows({ language, fromScheme: scheme, toScheme: destination, partOf: partof, creator, created }))
     }
+    if (opts.identifier) {
+      steps.push(new stream.Transform({
+        objectMode: true,
+        async transform(mapping, encoding, callback) {
+          try {
+            callback(null, await addMappingIdentifiers(mapping))
+          } catch(e) {
+            callback(e)
+          }
+        },
+      }))
+    }
     if (opts.validate) {
       steps.push(validator(opts))
     }
diff --git a/package-lock.json b/package-lock.json
index 24c8a51..01ba817 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -12,7 +12,7 @@
         "cocoda-sdk": "^3.4.13",
         "commander": "^12.1.0",
         "csv": "^6.4.1",
-        "jskos-tools": "^1.0.43",
+        "jskos-tools": "^1.2.0",
         "jskos-validate": "^1.2.0",
         "json-anystream": "^2.0.1",
         "jsonld": "^9.0.0",
@@ -2024,9 +2024,9 @@
       }
     },
     "node_modules/jskos-tools": {
-      "version": "1.1.0",
-      "resolved": "https://registry.npmjs.org/jskos-tools/-/jskos-tools-1.1.0.tgz",
-      "integrity": "sha512-Cg5Qd8cgb/s1voSEwbOzpcsXuq5ioy0FnM/00Hqngj6hV3Uq6oiwrwPBWHMU7x8kzlUpNnsS4LHoarO0TGRNoQ==",
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/jskos-tools/-/jskos-tools-1.2.0.tgz",
+      "integrity": "sha512-udxIM1287F9ICdYR8V0WZYwRgekBPrsUPsPJGfLBtTagE880ECTc6OcYVZ7l3cxjhzyzJKE1EfF5daNX0JePqQ==",
       "hasInstallScript": true,
       "license": "MIT"
     },
diff --git a/package.json b/package.json
index 9aa3726..6c6b0ae 100644
--- a/package.json
+++ b/package.json
@@ -57,7 +57,7 @@
     "cocoda-sdk": "^3.4.13",
     "commander": "^12.1.0",
     "csv": "^6.4.1",
-    "jskos-tools": "^1.0.43",
+    "jskos-tools": "^1.2.0",
     "jskos-validate": "^1.2.0",
     "json-anystream": "^2.0.1",
     "jsonld": "^9.0.0",
diff --git a/test/convert-mappings.js b/test/convert-mappings.js
index 38d9d2d..a0f415a 100644
--- a/test/convert-mappings.js
+++ b/test/convert-mappings.js
@@ -1,5 +1,5 @@
 import assert from "assert"
-import { ConceptScheme } from "jskos-tools"
+import { ConceptScheme, addMappingIdentifiers } from "jskos-tools"
 import mappingsFromRows from "../lib/csv-to-mapping.js"
 
 // { fromNotation: "612.111", toNotation: "4070945-0", type: "exact" }
@@ -81,4 +81,34 @@ describe("convert-mappings", () => {
 
     done()
   })
+
+  it("adds mapping sameness identifier", async () => {
+    const mapping = {
+      from: { memberSet: [{ uri: "http://example.org/voc/A1", notation: ["A1"] }] },
+      fromScheme: { uri: "http://example.org/voc" },
+      to: { memberSet: [{ uri: "http://example.com/voc/x", notation: ["x"] }] },
+      toScheme: { uri: "http://example.com/voc" },
+      type: ["http://www.w3.org/2004/02/skos/core#exactMatch"],
+    }
+    const result = await addMappingIdentifiers(mapping)
+    assert.ok(Array.isArray(result.identifier))
+    assert.ok(result.identifier.some(id => id.startsWith("mapping:")))
+    assert.ok(result.identifier.some(id => id.startsWith("urn:jskos:mapping:members:")))
+    assert.ok(result.identifier.some(id => id.startsWith("urn:jskos:mapping:content:")))
+  })
+
+  it("replaces existing mapping sameness identifier", async () => {
+    const mapping = {
+      from: { memberSet: [{ uri: "http://example.org/voc/A1", notation: ["A1"] }] },
+      fromScheme: { uri: "http://example.org/voc" },
+      to: { memberSet: [{ uri: "http://example.com/voc/x", notation: ["x"] }] },
+      toScheme: { uri: "http://example.com/voc" },
+      type: ["http://www.w3.org/2004/02/skos/core#exactMatch"],
+      identifier: ["mapping:oldid"],
+    }
+    const result = await addMappingIdentifiers(mapping)
+    const samenessIds = result.identifier.filter(id => id.startsWith("mapping:"))
+    assert.strictEqual(samenessIds.length, 1)
+    assert.ok(!samenessIds[0].includes("oldid"))
+  })
 })