diff --git a/Sources/ClassifierCreator.swift b/Sources/ClassifierCreator.swift
index 7be9e4f..ae70fd4 100644
--- a/Sources/ClassifierCreator.swift
+++ b/Sources/ClassifierCreator.swift
@@ -9,6 +9,8 @@ final class ClassifierCreator {
     private let sessionCheckpointIterations = 100
     private let sessionIterations = 1000
     
+    private let thumbnailSize = 100
+    
     let server: URL
     
     let configuration: Configuration
@@ -456,7 +458,7 @@ final class ClassifierCreator {
         
         let output = thumbnailDirectory.appendingPathComponent(String(format: "%04d.jpg", cap))
         do {
-            let command = "magick convert \(inputUrl.path) -quality 70% -resize 100x100 \(output.path)"
+            let command = "magick convert \(inputUrl.path) -quality 70% -resize \(thumbnailSize)x\(thumbnailSize) \(output.path)"
             let (code, output) = try safeShell(command)
             if code != 0 {
                 throw TrainingError.failedToCreateThumbnail(cap, output)