diff --git a/setup/config/config_mediaapi.go b/setup/config/config_mediaapi.go
index eeadc8945..0943a39e2 100644
--- a/setup/config/config_mediaapi.go
+++ b/setup/config/config_mediaapi.go
@@ -60,7 +60,7 @@ func (c *MediaAPI) Verify(configErrs *ConfigErrors, isMonolith bool) {
 	checkNotEmpty(configErrs, "media_api.base_path", string(c.BasePath))
 	// allow "unlimited" file size
 	if c.MaxFileSizeBytes != nil && *c.MaxFileSizeBytes <= 0 {
-		unlimitedSize := FileSizeBytes(math.MaxInt64)
+		unlimitedSize := FileSizeBytes(math.MaxInt64 - 1)
 		c.MaxFileSizeBytes = &unlimitedSize
 	}
 	checkPositive(configErrs, "media_api.max_file_size_bytes", int64(*c.MaxFileSizeBytes))