diff --git a/src/cargo/core/source_id.rs b/src/cargo/core/source_id.rs
index ca022c936590..68f916b36b5a 100644
--- a/src/cargo/core/source_id.rs
+++ b/src/cargo/core/source_id.rs
@@ -787,15 +787,23 @@ mod tests {
     // changing and why the old value can't be easily preserved.
     //
     // The hash value should be stable across platforms, and doesn't depend on
-    // endianness and bit-width.
+    // endianness and bit-width. One caveat is that absolute paths is inherently
+    // different on Windows than on Unix-like platforms. Unless we omit or strip
+    // the prefix components (e.g. `C:`), there is not way to have a
+    // cross-platform stable hash for absolute paths.
     #[test]
     fn test_stable_hash() {
         use crate::util::StableHasher;
         use std::path::Path;
 
+        #[cfg(not(windows))]
+        let ws_root = Path::new("/tmp/ws");
+        #[cfg(windows)]
+        let ws_root = Path::new(r"C:\tmp\ws");
+
         let gen_hash = |source_id: SourceId| {
             let mut hasher = StableHasher::new();
-            source_id.stable_hash(Path::new("/tmp/ws"), &mut hasher);
+            source_id.stable_hash(ws_root, &mut hasher);
             hasher.finish()
         };
 
@@ -828,8 +836,7 @@ mod tests {
         assert_eq!(gen_hash(source_id), 3109465066469481245);
         assert_eq!(crate::util::hex::short_hash(&source_id), "1d5b66d8000a272b");
 
-        let path = Path::new("/tmp/ws/crate");
-
+        let path = &ws_root.join("crate");
         let source_id = SourceId::for_local_registry(path).unwrap();
         assert_eq!(gen_hash(source_id), 17171351456028149232);
         assert_eq!(crate::util::hex::short_hash(&source_id), "f0c5f1e92be54cee");