diff --git a/tvix/eval/src/lib.rs b/tvix/eval/src/lib.rs
index 845964cb7..398da4d6e 100644
--- a/tvix/eval/src/lib.rs
+++ b/tvix/eval/src/lib.rs
@@ -29,7 +29,7 @@ mod vm;
 mod warnings;
 
 mod nix_search_path;
-#[cfg(test)]
+#[cfg(all(test, feature = "arbitrary"))]
 mod properties;
 #[cfg(test)]
 mod test_utils;
diff --git a/tvix/eval/src/value/string.rs b/tvix/eval/src/value/string.rs
index e3e92865f..0b37d483b 100644
--- a/tvix/eval/src/value/string.rs
+++ b/tvix/eval/src/value/string.rs
@@ -883,7 +883,7 @@ impl Display for NixString {
     }
 }
 
-#[cfg(test)]
+#[cfg(all(test, feature = "arbitrary"))]
 mod tests {
     use test_strategy::proptest;