diff --git a/conformance/probe/Cargo.lock b/conformance/probe/Cargo.lock
index 964e0ab..36cfe85 100644
--- a/conformance/probe/Cargo.lock
+++ b/conformance/probe/Cargo.lock
@@ -64,6 +64,7 @@ dependencies = [
  "bzip2",
  "flate2",
  "libaec-sys",
+ "libc",
  "lz4_flex",
  "pco",
  "portable-atomic",