diff --git a/lib/index.js b/lib/index.js
index 24c488b..6dde0b1 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -90,7 +90,7 @@ function assert(check, message) {
 function initSet(peer, config) {
   assertDBPlugin(peer)
 
-  const ghostSpan = config.set?.ghostSpan ?? 32
+  let ghostSpan = config.set?.ghostSpan ?? 32
   if (ghostSpan < 1) throw new Error('config.set.ghostSpan must be >= 0')
 
   //#region state
@@ -531,6 +531,15 @@ function initSet(peer, config) {
     return ghostSpan
   }
 
+  /**
+   * @param {number} span
+   * @returns {void}
+   */
+  function setGhostSpan(span) {
+    if (span < 1) throw new Error('ghostSpan must be >= 0')
+    ghostSpan = span
+  }
+
   /**
    * @param {any} subdomain
    */
@@ -583,6 +592,7 @@ function initSet(peer, config) {
     getFeedID,
     isGhostable,
     getGhostSpan,
+    setGhostSpan,
     minGhostDepth,
     minRequiredDepth,
     squeeze,
diff --git a/test/index.test.js b/test/index.test.js
index 806ddd7..78de184 100644
--- a/test/index.test.js
+++ b/test/index.test.js
@@ -19,7 +19,7 @@ test('setup', async (t) => {
   peer = createPeer({
     keypair: aliceKeypair,
     db: { path: DIR },
-    set: { ghostSpan: 4 },
+    set: { ghostSpan: 40 },
   })
 
   await peer.db.loaded()
@@ -30,6 +30,7 @@ test('setup', async (t) => {
   })
   await p(peer.set.load)(aliceID)
 
+  peer.set.setGhostSpan(4)
   assert.equal(peer.set.getGhostSpan(), 4, 'getGhostSpan')
 })