diff --git a/src/Model/Model_Font_Downloader.php b/src/Model/Model_Font_Downloader.php
index 4039902fb..a1308c9e8 100644
--- a/src/Model/Model_Font_Downloader.php
+++ b/src/Model/Model_Font_Downloader.php
@@ -802,8 +802,8 @@ protected function get_size_fields( array $files, string $dir ): array {
 
 	/**
 	 * Delete an unused downloaded family's own copies (see Model_Font_Sources::get_own_copy()), keeping the licence files
-	 * and any other font's file at a family file's name. A file at the name another site's custom font uses is kept too,
-	 * as every site shares the fonts folder.
+	 * and any other font's file at a family file's name (a file of a known size is hashed to tell). A file at the name
+	 * another site's custom font uses is kept too, as every site shares the fonts folder.
 	 *
 	 * @return array{id: string, removed: string[], bytes: int, font: array|null}|WP_Error `font` is its row now, if it can
 	 *                                                                                     be installed again. 404 when
@@ -813,6 +813,15 @@ protected function get_size_fields( array $files, string $dir ): array {
 	 */
 	public function delete_downloaded_font( string $key ) {
 		$family = $this->get_core_families()[ $key ] ?? null;
+
+		/* Before the sync saves the font under its hashed name, another font's file of a known size passes for its own */
+		foreach ( $family['paths'] ?? [] as $file => $path ) {
+			if ( $path === $this->font_sources->get_plain_path( $file ) && $this->is_unknown_build( $file ) ) {
+				unset( $family['paths'][ $file ] );
+				$this->log->notice( 'Kept another font\'s file at a font file\'s name', [ 'name' => $file ] );
+			}
+		}
+
 		if ( $family === null || count( $family['paths'] ) === 0 ) {
 			return new WP_Error( 'font_not_downloaded', __( 'The font is not downloaded.', 'gravity-pdf' ), [ 'status' => 404 ] );
 		}
diff --git a/tests/phpunit/integration/Model/Test_Downloaded_Fonts.php b/tests/phpunit/integration/Model/Test_Downloaded_Fonts.php
index 3e49ed9db..840ef3240 100644
--- a/tests/phpunit/integration/Model/Test_Downloaded_Fonts.php
+++ b/tests/phpunit/integration/Model/Test_Downloaded_Fonts.php
@@ -381,6 +381,15 @@ public function test_delete_removes_only_the_hashed_copy_and_never_the_file_at_t
 		$this->assertFileEquals( $this->font_fixture( 'Chewy.ttf' ), $this->font_path( 'DejaVuSerifCondensed.ttf' ) );
 	}
 
+	public function test_delete_keeps_another_fonts_file_of_a_known_size_at_the_name() {
+		$this->put_same_size_font_at( 'DejaVuSerifCondensed.ttf', 'DejaVuSerifCondensed.ttf' );
+		$bytes = (string) file_get_contents( $this->font_path( 'DejaVuSerifCondensed.ttf' ) );
+
+		$this->assert_font_error( $this->downloader()->delete_downloaded_font( 'dejavuserifcondensed' ), 'font_not_downloaded', 404 );
+		$this->assertStringEqualsFile( $this->font_path( 'DejaVuSerifCondensed.ttf' ), $bytes );
+		$this->assertCount( 1, $this->log_messages( 'Kept another font\'s file at a font file\'s name' ) );
+	}
+
 	public function test_a_family_sharing_a_name_with_a_record_lists_and_deletes_only_its_hashed_copy() {
 		$sources = GPDFAPI::get_mvc_class( 'Model_Font_Sources' );
 		$hashed  = $sources->get_hashed_name( 'DejaVuSerifCondensed.ttf' );
diff --git a/tests/playwright/core/managers/font-manager.spec.ts b/tests/playwright/core/managers/font-manager.spec.ts
index 7b70de063..6c9f60cfa 100644
--- a/tests/playwright/core/managers/font-manager.spec.ts
+++ b/tests/playwright/core/managers/font-manager.spec.ts
@@ -4,7 +4,7 @@ import type { Page } from '@playwright/test';
 import { test, resourcesPath } from '@self:playwright/fixtures/test';
 import Pdf, { type FontUpload } from '@self:playwright/utils/gravitypdf';
 import { wpCli } from '@self:playwright/utils/wp-cli';
-import { coreFontStandIn } from '@self:playwright/utils/core-fonts';
+import { coreFontStandIn, hashedName } from '@self:playwright/utils/core-fonts';
 import * as fs from 'fs';
 import * as path from 'path';
 
@@ -379,7 +379,7 @@ test.describe('Font Manager', () => {
 
 		// Seeds a core font no other spec uses
 		const seedCoreFont = (...files: string[]) => {
-			seededFiles.push(...files);
+			seededFiles.push(...files.map(hashedName));
 			wpCli(
 				...files.map((file) =>
 					coreFontStandIn(
diff --git a/tests/playwright/multisite/site-fonts.spec.ts b/tests/playwright/multisite/site-fonts.spec.ts
index 21238e7ce..7a56961cb 100644
--- a/tests/playwright/multisite/site-fonts.spec.ts
+++ b/tests/playwright/multisite/site-fonts.spec.ts
@@ -6,7 +6,7 @@ import {
 	logInToSubsite as logIn,
 } from '@self:playwright/utils/multisite';
 import { wpCli } from '@self:playwright/utils/wp-cli';
-import { coreFontStandIn } from '@self:playwright/utils/core-fonts';
+import { coreFontStandIn, hashedName } from '@self:playwright/utils/core-fonts';
 import * as fs from 'fs';
 import * as path from 'path';
 
@@ -17,6 +17,10 @@ const FILE = 'NetworkRoboto.ttf';
 const CORE_NAMED_FONT = 'Core Named Roboto';
 const CORE_FILE = 'DejaVuSerifCondensed.ttf';
 const CORE_BOLD_FILE = 'DejaVuSerifCondensed-Bold.ttf';
+const CORE_BOLD_COPY = hashedName(CORE_BOLD_FILE);
+// The manifest's own build, which the plugin hashes before deleting it from the core font's name
+const CORE_FILE_IN_CONTAINER =
+	'wp-content/plugins/gravity-pdf/tools/phpunit/data/fonts/DejaVuSerifCondensed.ttf';
 const ROBOTO_IN_CONTAINER =
 	'wp-content/plugins/gravity-pdf/tools/playwright/data/fonts/Roboto-Regular.ttf';
 
@@ -83,7 +87,7 @@ test.describe('Fonts of a Multisite subsite', () => {
 		}
 
 		await admin.context().close();
-		wpCli(`rm -f ${FONTS}/${CORE_FILE} ${FONTS}/${CORE_BOLD_FILE}`);
+		wpCli(`rm -f ${FONTS}/${CORE_FILE} ${FONTS}/${CORE_BOLD_COPY}`);
 	};
 
 	test.beforeAll(deleteFonts);
@@ -207,7 +211,7 @@ test.describe('Fonts of a Multisite subsite', () => {
 			(row: { id: string }) => row.id === 'dejavuserifcondensed'
 		);
 		expect(core.regular).toBe('');
-		expect(core.bold).toBe(CORE_BOLD_FILE);
+		expect(core.bold).toBe(CORE_BOLD_COPY);
 
 		const deleted = await send(
 			page,
@@ -222,7 +226,7 @@ test.describe('Fonts of a Multisite subsite', () => {
 
 		const files = fontFileList();
 		expect(files).toContain(CORE_FILE);
-		expect(files).not.toContain(CORE_BOLD_FILE);
+		expect(files).not.toContain(CORE_BOLD_COPY);
 
 		// Throws if the subsite's font no longer has its own bytes
 		wpCli(`cmp ${ROBOTO_IN_CONTAINER} ${FONTS}/${CORE_FILE}`);
@@ -249,7 +253,7 @@ test.describe('Fonts of a Multisite subsite', () => {
 		await subsite.context().close();
 
 		// The custom font's delete removed its file, so put one back at the core font's name
-		wpCli(coreFontStandIn(ROBOTO_IN_CONTAINER, `${FONTS}/${CORE_FILE}`));
+		wpCli(`cp ${CORE_FILE_IN_CONTAINER} ${FONTS}/${CORE_FILE}`);
 
 		await page.goto('/wp-admin/index.php');
 		const deleted = await send(
diff --git a/tools/playwright/utils/core-fonts.ts b/tools/playwright/utils/core-fonts.ts
index 8f9062b8f..fb55d6159 100644
--- a/tools/playwright/utils/core-fonts.ts
+++ b/tools/playwright/utils/core-fonts.ts
@@ -1,26 +1,45 @@
 import * as fs from 'fs';
 import * as path from 'path';
 
-const manifest: { name: string; size: number }[] = JSON.parse(
+const manifest: { name: string; size: number; sha: string }[] = JSON.parse(
 	fs.readFileSync(
 		path.join(__dirname, '..', '..', '..', 'fonts', 'core-fonts.json'),
 		'utf8'
 	)
 );
 
+const entryFor = (file: string) => {
+	const entry = manifest.find((row) => row.name === file);
+	if (entry === undefined) {
+		throw new Error(`${file} is not on the core font manifest`);
+	}
+
+	return entry;
+};
+
+/**
+ * The name a core font file takes when another file holds its own: `{stem}-{first 8 of its SHA-1}{ext}`
+ *
+ * @param file The core font file's name
+ */
+export function hashedName(file: string) {
+	const { ext, name } = path.parse(file);
+
+	return `${name}-${entryFor(file).sha.slice(0, 8)}${ext}`;
+}
+
 /**
- * A shell command putting a stand-in for a core font file at `dest`: a copy of `source` at the core file's size on the
- * manifest, which the plugin takes as the core font's own copy (downloads are off on the E2E sites)
+ * A shell command putting a stand-in for a core font file under its hashed name (see hashedName()) beside `dest`: a
+ * copy of `source` at the core file's size on the manifest. The plugin takes a hashed copy of that size as the core
+ * font's own without hashing it, while one at the plain name is hashed before it's deleted (downloads are off on the
+ * E2E sites).
  *
  * @param source A font file path in the container
  * @param dest   The core font file's path in the container
  */
 export function coreFontStandIn(source: string, dest: string) {
 	const file = path.basename(dest);
-	const size = manifest.find((entry) => entry.name === file)?.size;
-	if (size === undefined) {
-		throw new Error(`${file} is not on the core font manifest`);
-	}
+	const target = path.join(path.dirname(dest), hashedName(file));
 
-	return `cp ${source} ${dest} && truncate -s ${size} ${dest}`;
+	return `cp ${source} ${target} && truncate -s ${entryFor(file).size} ${target}`;
 }