diff --git a/Cargo.lock b/Cargo.lock
index c6e4379..60f46de 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -948,7 +948,7 @@ dependencies = [
 
 [[package]]
 name = "vtracer-bench"
-version = "1.0.0-alpha.5"
+version = "1.0.0-alpha.6"
 dependencies = [
  "dssim-core",
  "image",
diff --git a/crates/vtracer-bench/Cargo.toml b/crates/vtracer-bench/Cargo.toml
index f6d6433..473972c 100644
--- a/crates/vtracer-bench/Cargo.toml
+++ b/crates/vtracer-bench/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "vtracer-bench"
 description = "Blind fidelity benchmark for raster-to-vector tracers: compare the original raster with a rendered reconstruction and get one 0..1 fidelity score built from PSNR, SSIM and a clustered-diff patch metric."
-version = "1.0.0-alpha.5"
+version = "1.0.0-alpha.6"
 authors.workspace = true
 edition.workspace = true
 license.workspace = true
@@ -23,6 +23,7 @@ required-features = ["cli"]
 
 [dependencies]
 visioncortex.workspace = true
-dssim-core = { version = "3", default-features = false }
+# ~3.4: the only line whose no-`threads` fallback compiles (3.3 and 3.5 both fail)
+dssim-core = { version = "~3.4", default-features = false }
 rgb = "0.8"
 image = { version = "0.25", default-features = false }