diff --git a/apps/server/src/services/custom_dictionary.spec.ts b/apps/server/src/services/custom_dictionary.spec.ts
index 9d94dc79ab..2f74fd41aa 100644
--- a/apps/server/src/services/custom_dictionary.spec.ts
+++ b/apps/server/src/services/custom_dictionary.spec.ts
@@ -24,7 +24,8 @@ vi.mock("./sql.js", () => ({
 function mockSession(localWords: string[] = []) {
     return {
         listWordsInSpellCheckerDictionary: vi.fn().mockResolvedValue(localWords),
-        addWordToSpellCheckerDictionary: vi.fn()
+        addWordToSpellCheckerDictionary: vi.fn(),
+        removeWordFromSpellCheckerDictionary: vi.fn()
     } as any;
 }
 
@@ -47,6 +48,7 @@ describe("custom_dictionary", () => {
             await customDictionary.loadForSession(session);
 
             expect(session.addWordToSpellCheckerDictionary).not.toHaveBeenCalled();
+            expect(session.removeWordFromSpellCheckerDictionary).not.toHaveBeenCalled();
         });
 
         it("imports local words when note is empty (one-time import)", async () => {
@@ -59,6 +61,16 @@ describe("custom_dictionary", () => {
             expect(session.addWordToSpellCheckerDictionary).toHaveBeenCalledWith("world");
         });
 
+        it("clears local dictionary after one-time import", async () => {
+            const session = mockSession(["hello", "world"]);
+
+            await customDictionary.loadForSession(session);
+
+            expect(session.removeWordFromSpellCheckerDictionary).toHaveBeenCalledTimes(2);
+            expect(session.removeWordFromSpellCheckerDictionary).toHaveBeenCalledWith("hello");
+            expect(session.removeWordFromSpellCheckerDictionary).toHaveBeenCalledWith("world");
+        });
+
         it("loads note words into session when no local words exist", async () => {
             becca.reset();
             buildNote({
@@ -91,6 +103,23 @@ describe("custom_dictionary", () => {
             expect(session.addWordToSpellCheckerDictionary).toHaveBeenCalledTimes(3);
         });
 
+        it("clears local dictionary after merging", async () => {
+            becca.reset();
+            buildNote({
+                id: "_customDictionary",
+                title: "Custom Dictionary",
+                type: "code",
+                content: "apple\nbanana"
+            });
+            const session = mockSession(["banana", "cherry"]);
+
+            await customDictionary.loadForSession(session);
+
+            expect(session.removeWordFromSpellCheckerDictionary).toHaveBeenCalledTimes(2);
+            expect(session.removeWordFromSpellCheckerDictionary).toHaveBeenCalledWith("banana");
+            expect(session.removeWordFromSpellCheckerDictionary).toHaveBeenCalledWith("cherry");
+        });
+
         it("does not save when local words are a subset of note words", async () => {
             becca.reset();
             buildNote({
@@ -104,6 +133,7 @@ describe("custom_dictionary", () => {
             await customDictionary.loadForSession(session);
 
             expect(session.addWordToSpellCheckerDictionary).toHaveBeenCalledTimes(3);
+            expect(session.removeWordFromSpellCheckerDictionary).toHaveBeenCalledTimes(2);
         });
 
         it("handles note with whitespace and blank lines", async () => {
diff --git a/apps/server/src/services/custom_dictionary.ts b/apps/server/src/services/custom_dictionary.ts
index c8f2748fdd..770cefb81e 100644
--- a/apps/server/src/services/custom_dictionary.ts
+++ b/apps/server/src/services/custom_dictionary.ts
@@ -52,6 +52,17 @@ function addWord(word: string) {
     saveWords(words);
 }
 
+/**
+ * Removes all words from Electron's local spellchecker dictionary
+ * so they are not re-imported on subsequent startups.
+ */
+function clearFromLocalDictionary(session: Session, localWords: string[]) {
+    for (const word of localWords) {
+        session.removeWordFromSpellCheckerDictionary(word);
+    }
+    log.info(`Cleared ${localWords.length} words from local spellchecker dictionary.`);
+}
+
 /**
  * Loads the custom dictionary into Electron's spellchecker session,
  * performing a one-time import of locally stored words on first use.
@@ -73,6 +84,7 @@ async function loadForSession(session: Session) {
         log.info(`Importing ${localWords.length} words from local spellchecker dictionary.`);
         merged = new Set(localWords);
         saveWords(merged);
+        clearFromLocalDictionary(session, localWords);
     } else if (noteWords.size > 0 && localWords.length > 0) {
         // Merge both sources so no words are lost.
         const before = noteWords.size;
@@ -83,6 +95,7 @@ async function loadForSession(session: Session) {
             log.info(`Merged ${merged.size - before} new words from local dictionary.`);
             saveWords(merged);
         }
+        clearFromLocalDictionary(session, localWords);
     }
 
     // Load all words into Electron's spellchecker.