diff --git a/src/cargo/ops/cargo_new.rs b/src/cargo/ops/cargo_new.rs
index b78ba243e3eb..58c13aa6cebe 100644
--- a/src/cargo/ops/cargo_new.rs
+++ b/src/cargo/ops/cargo_new.rs
@@ -960,9 +960,6 @@ fn update_manifest_with_new_member(
             workspace_root.display()
         )
     })?;
-    let relpath = relpath
-        .to_str()
-        .with_context(|| format!("invalid non-unicode path `{}`", relpath.display()))?;
 
     // Don't add the new package to the workspace's members
     // if there is an exclusion match for it.
@@ -972,13 +969,20 @@ fn update_manifest_with_new_member(
         .and_then(|members| members.as_array())
     {
         for member in members {
-            let pat = member.as_str().unwrap();
-            if pat == relpath {
+            let pat = member
+                .as_str()
+                .with_context(|| format!("invalid members' element `{}`", member))?;
+            if Path::new(pat) == relpath {
                 return Ok(());
             }
         }
     }
 
+    let display_path = relpath
+        .to_str()
+        .map(|s| s.replace('\\', "/"))
+        .with_context(|| format!("invalid non-unicode path `{}`", relpath.display()))?;
+
     // If the members element already exist, check if one of the patterns
     // in the array already includes the new package's relative path.
     // - Add the relative path if the members don't match the new package's path.
@@ -993,7 +997,7 @@ fn update_manifest_with_new_member(
             let pattern = glob::Pattern::new(pat)
                 .with_context(|| format!("cannot build glob pattern from `{}`", pat))?;
 
-            if pattern.matches(relpath) {
+            if pattern.matches_path(&relpath) {
                 return Ok(());
             }
         }
@@ -1007,7 +1011,7 @@ fn update_manifest_with_new_member(
             anyhow::bail!("[workspace.members] is not an array");
         };
 
-        toml_members.push(relpath);
+        toml_members.push(&display_path);
 
         if let Some(decor) = decor {
             if let Some(last) = toml_members
@@ -1041,7 +1045,7 @@ fn update_manifest_with_new_member(
         }
 
         let mut array = Array::new();
-        array.push(relpath);
+        array.push(&display_path);
         if !assume_new_line {
             array.decor_mut().set_suffix("\n");
         }
@@ -1052,7 +1056,7 @@ fn update_manifest_with_new_member(
         ws.insert("members", toml_edit::value(array));
     } else {
         let mut array = Array::new();
-        array.push(relpath);
+        array.push(&display_path);
         array.decor_mut().set_suffix("\n");
         workspace_document["workspace"]["members"] = toml_edit::value(array);
     }