diff --git a/Tests/KeystoneTests/Tests/Services/MediaCreateParamsFilePathTests.swift b/Tests/KeystoneTests/Tests/Services/MediaCreateParamsFilePathTests.swift
new file mode 100644
index 000000000000..e1050287d328
--- /dev/null
+++ b/Tests/KeystoneTests/Tests/Services/MediaCreateParamsFilePathTests.swift
@@ -0,0 +1,41 @@
+import Foundation
+import Testing
+import WordPressAPI
+import WordPressKit
+
+@testable import WordPress
+
+/// `URL.path()` percent-encodes by default, unlike the legacy `url.path` property, so the
+/// upload API was handed a path that doesn't exist on disk whenever the filename needed
+/// encoding. A space is enough, which makes it reachable with ordinary content.
+struct MediaCreateParamsFilePathTests {
+
+    @Test func decodesPercentEncodingInTheFilePath() throws {
+        let media = RemoteMedia()
+        media.localURL = URL(fileURLWithPath: "/tmp/media/screen recording 1.mp4")
+
+        let params = try #require(MediaCreateParams(media: media))
+
+        #expect(params.filePath == "/tmp/media/screen recording 1.mp4")
+    }
+
+    /// Characters beyond the space get encoded too, so check one of those as well.
+    @Test func decodesPercentEncodingBeyondSpaces() throws {
+        let media = RemoteMedia()
+        media.localURL = URL(fileURLWithPath: "/tmp/media/100% done.jpg")
+
+        let params = try #require(MediaCreateParams(media: media))
+
+        #expect(params.filePath == "/tmp/media/100% done.jpg")
+    }
+
+    /// A name needing no encoding has to survive untouched.
+    @Test func leavesAnOrdinaryPathAlone() throws {
+        let media = RemoteMedia()
+        media.localURL = URL(fileURLWithPath: "/tmp/media/IMG_0001.jpg")
+
+        let params = try #require(MediaCreateParams(media: media))
+
+        #expect(params.filePath == "/tmp/media/IMG_0001.jpg")
+    }
+}
diff --git a/WordPress/Classes/Services/MediaServiceRemoteCoreREST.swift b/WordPress/Classes/Services/MediaServiceRemoteCoreREST.swift
index aa1d060c0066..394caa07214a 100644
--- a/WordPress/Classes/Services/MediaServiceRemoteCoreREST.swift
+++ b/WordPress/Classes/Services/MediaServiceRemoteCoreREST.swift
@@ -176,7 +176,9 @@ private extension RemoteMedia {
     }
 }
 
-private extension MediaCreateParams {
+// Not `private`: the file-path handling below is covered by
+// `MediaCreateParamsFilePathTests`.
+extension MediaCreateParams {
     init?(media: RemoteMedia) {
 
         guard let localURL = media.localURL else {
@@ -198,7 +200,9 @@ private extension MediaCreateParams {
             caption: media.caption,
             description: media.descriptionText,
             postId: media.postID?.int64Value,
-            filePath: localURL.path()
+            // `path()` percent-encodes by default, so a filename with a space (a screen
+            // recording, say) becomes a path that doesn't exist on disk.
+            filePath: localURL.path(percentEncoded: false)
         )
     }
 }