diff --git a/crates/cargo-test-support/Cargo.toml b/crates/cargo-test-support/Cargo.toml
index 64c1f3c5f9b..81ef1bcb703 100644
--- a/crates/cargo-test-support/Cargo.toml
+++ b/crates/cargo-test-support/Cargo.toml
@@ -25,5 +25,8 @@ termcolor = "1.1.2"
 toml_edit = { version = "0.14.3", features = ["serde", "easy", "perf"] }
 url = "2.2.2"
 
+[target.'cfg(windows)'.dependencies]
+winapi = "0.3"
+
 [features]
 deny-warnings = []
diff --git a/crates/cargo-test-support/src/paths.rs b/crates/cargo-test-support/src/paths.rs
index 29b3687969b..b1c62b99e6a 100644
--- a/crates/cargo-test-support/src/paths.rs
+++ b/crates/cargo-test-support/src/paths.rs
@@ -287,3 +287,54 @@ pub fn sysroot() -> String {
     let sysroot = String::from_utf8(output.stdout).unwrap();
     sysroot.trim().to_string()
 }
+
+/// Returns true if names such as aux.* are allowed.
+///
+/// Traditionally, Windows did not allow a set of file names (see `is_windows_reserved`
+/// for a list). More recent versions of Windows have relaxed this restriction. This test
+/// determines whether we are running in a mode that allows Windows reserved names.
+#[cfg(windows)]
+pub fn windows_reserved_names_are_allowed() -> bool {
+    use std::ffi::OsStr;
+    use std::os::windows::ffi::OsStrExt;
+    use std::ptr;
+    use winapi::um::fileapi::GetFullPathNameW;
+
+    let test_file_name: Vec<_> = OsStr::new("aux.rs").encode_wide().collect();
+
+    let buffer_length =
+        unsafe { GetFullPathNameW(test_file_name.as_ptr(), 0, ptr::null_mut(), ptr::null_mut()) };
+
+    if buffer_length == 0 {
+        // This means the call failed, so we'll conservatively assume reserved names are not allowed.
+        return false;
+    }
+
+    let mut buffer = vec![0u16; buffer_length as usize];
+
+    let result = unsafe {
+        GetFullPathNameW(
+            test_file_name.as_ptr(),
+            buffer_length,
+            buffer.as_mut_ptr(),
+            ptr::null_mut(),
+        )
+    };
+
+    if result == 0 {
+        // Once again, conservatively assume reserved names are not allowed if the
+        // GetFullPathNameW call failed.
+        return false;
+    }
+
+    // Under the old rules, a file name like aux.rs would get converted into \\.\aux, so
+    // we detect this case by checking if the string starts with \\.\
+    //
+    // Otherwise, the filename will be something like C:\Users\Foo\Documents\aux.rs
+    let prefix: Vec<_> = OsStr::new("\\\\.\\").encode_wide().collect();
+    if buffer.starts_with(&prefix) {
+        false
+    } else {
+        true
+    }
+}
diff --git a/src/cargo/util/restricted_names.rs b/src/cargo/util/restricted_names.rs
index 16b047bd8c3..650ae233059 100644
--- a/src/cargo/util/restricted_names.rs
+++ b/src/cargo/util/restricted_names.rs
@@ -97,59 +97,3 @@ pub fn is_windows_reserved_path(path: &Path) -> bool {
 pub fn is_glob_pattern<T: AsRef<str>>(name: T) -> bool {
     name.as_ref().contains(&['*', '?', '[', ']'][..])
 }
-
-/// Returns true if names such as aux.* are allowed.
-///
-/// Traditionally, Windows did not allow a set of file names (see `is_windows_reserved`
-/// for a list). More recent versions of Windows have relaxed this restriction. This test
-/// determines whether we are running in a mode that allows Windows reserved names.
-pub fn windows_reserved_names_are_allowed() -> bool {
-    #[cfg(windows)]
-    {
-        use std::ffi::OsStr;
-        use std::os::windows::ffi::OsStrExt;
-        use std::ptr;
-        use winapi::um::fileapi::GetFullPathNameW;
-
-        let test_file_name: Vec<_> = OsStr::new("aux.rs").encode_wide().collect();
-
-        let buffer_length = unsafe {
-            GetFullPathNameW(test_file_name.as_ptr(), 0, ptr::null_mut(), ptr::null_mut())
-        };
-
-        if buffer_length == 0 {
-            // This means the call failed, so we'll conservatively assume reserved names are not allowed.
-            return false;
-        }
-
-        let mut buffer = vec![0u16; buffer_length as usize];
-
-        let result = unsafe {
-            GetFullPathNameW(
-                test_file_name.as_ptr(),
-                buffer_length,
-                buffer.as_mut_ptr(),
-                ptr::null_mut(),
-            )
-        };
-
-        if result == 0 {
-            // Once again, conservatively assume reserved names are not allowed if the
-            // GetFullPathNameW call failed.
-            return false;
-        }
-
-        // Under the old rules, a file name like aux.rs would get converted into \\.\aux, so
-        // we detect this case by checking if the string starts with \\.\
-        //
-        // Otherwise, the filename will be something like C:\Users\Foo\Documents\aux.rs
-        let prefix: Vec<_> = OsStr::new("\\\\.\\").encode_wide().collect();
-        if buffer.starts_with(&prefix) {
-            false
-        } else {
-            true
-        }
-    }
-    #[cfg(not(windows))]
-    true
-}
diff --git a/tests/testsuite/package.rs b/tests/testsuite/package.rs
index 19ae6c639c7..63e384af88e 100644
--- a/tests/testsuite/package.rs
+++ b/tests/testsuite/package.rs
@@ -2011,7 +2011,7 @@ src/lib.rs
 fn reserved_windows_name() {
     // If we are running on a version of Windows that allows these reserved filenames,
     // skip this test.
-    if cargo::util::restricted_names::windows_reserved_names_are_allowed() {
+    if paths::windows_reserved_names_are_allowed() {
         return;
     }