diff --git a/cargo-miri/bin.rs b/cargo-miri/bin.rs
index 480dd63859..39f8dcf17e 100644
--- a/cargo-miri/bin.rs
+++ b/cargo-miri/bin.rs
@@ -882,26 +882,34 @@ fn phase_cargo_rustdoc(fst_arg: &str, mut args: env::Args) {
 
     // Because of the way the main function is structured, we have to take the first argument spearately
     // from the rest; to simplify the following argument patching loop, we'll just skip that one.
-    // This is fine for now, because cargo will never pass the relevant arguments in the first position,
+    // This is fine for now, because cargo will never pass --extern arguments in the first position,
     // but we should defensively assert that this will work.
     let extern_flag = "--extern";
-    let runtool_flag = "--runtool";
     assert!(fst_arg != extern_flag);
-    assert!(fst_arg != runtool_flag);
     cmd.arg(fst_arg);
-
+    
+    let runtool_flag = "--runtool";
+    let mut crossmode = fst_arg == runtool_flag;
     while let Some(arg) = args.next() {
         if arg == extern_flag {
             // Patch --extern arguments to use *.rmeta files, since phase_cargo_rustc only creates stub *.rlib files.
             forward_patched_extern_arg(&mut args, &mut cmd);
         } else if arg == runtool_flag {
-            // Do not forward an existing --runtool argument, since we will set this ourselves
-            let _ = args.next().expect("`--runtool` should be followed by an executable name");
+            // An existing --runtool flag indicates cargo is running in cross-target mode, which we don't support.
+            // Note that this is only passed when cargo is run with the unstable -Zdoctest-xcompile flag;
+            // otherwise, we won't be called as rustdoc at all.
+            crossmode = true;
+            break;
         } else {
             cmd.arg(arg);
         }
     }
 
+    if crossmode {
+        eprintln!("Cross-interpreting doc-tests is not currently supported by Miri.");
+        return;
+    }
+
     // For each doc-test, rustdoc starts two child processes: first the test is compiled,
     // then the produced executable is invoked. We want to reroute both of these to cargo-miri,
     // such that the first time we'll enter phase_cargo_rustc, and phase_cargo_runner second.
diff --git a/test-cargo-miri/run-test.py b/test-cargo-miri/run-test.py
index d32afa6a8a..df0b736028 100755
--- a/test-cargo-miri/run-test.py
+++ b/test-cargo-miri/run-test.py
@@ -16,13 +16,13 @@ def fail(msg):
     sys.exit(1)
 
 def cargo_miri(cmd):
-    args = ["cargo", "+nightly", "miri", cmd, "-q"]
+    args = ["cargo", "miri", cmd, "-q"]
     if 'MIRI_TEST_TARGET' in os.environ:
-        args += ["-Zdoctest-xcompile"]
         args += ["--target", os.environ['MIRI_TEST_TARGET']]
     return args
 
 def normalize_stdout(str):
+    str = str.replace("src\\", "src/") # normalize paths across platforms
     return re.sub("finished in \d+\.\d\ds", "finished in $TIME", str)
 
 def test(name, cmd, stdout_ref, stderr_ref, stdin=b'', env={}):
@@ -73,24 +73,29 @@ def test_cargo_miri_run():
     )
 
 def test_cargo_miri_test():
+    # rustdoc is not run on foreign targets
+    is_foreign = 'MIRI_TEST_TARGET' in os.environ
+    default_ref = "test.cross-target.stdout.ref" if is_foreign else "test.default.stdout.ref"
+    filter_ref = "test.filter.cross-target.stdout.ref" if is_foreign else "test.filter.stdout.ref"
+
     test("`cargo miri test`",
         cargo_miri("test"),
-        "test.default.stdout.ref", "test.stderr-empty.ref",
+        default_ref, "test.stderr-empty.ref",
         env={'MIRIFLAGS': "-Zmiri-seed=feed"},
     )
     test("`cargo miri test` (no isolation)",
         cargo_miri("test"),
-        "test.default.stdout.ref", "test.stderr-empty.ref",
+        default_ref, "test.stderr-empty.ref",
         env={'MIRIFLAGS': "-Zmiri-disable-isolation"},
     )
     test("`cargo miri test` (raw-ptr tracking)",
         cargo_miri("test"),
-        "test.default.stdout.ref", "test.stderr-empty.ref",
+        default_ref, "test.stderr-empty.ref",
         env={'MIRIFLAGS': "-Zmiri-track-raw-pointers"},
     )
     test("`cargo miri test` (with filter)",
         cargo_miri("test") + ["--", "--format=pretty", "le1"],
-        "test.filter.stdout.ref", "test.stderr-empty.ref",
+        filter_ref, "test.stderr-empty.ref",
     )
     test("`cargo miri test` (test target)",
         cargo_miri("test") + ["--test", "test", "--", "--format=pretty"],
diff --git a/test-cargo-miri/test.cross-target.stdout.ref b/test-cargo-miri/test.cross-target.stdout.ref
new file mode 100644
index 0000000000..7079798e42
--- /dev/null
+++ b/test-cargo-miri/test.cross-target.stdout.ref
@@ -0,0 +1,10 @@
+
+running 1 test
+.
+test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
+
+
+running 7 tests
+..i....
+test result: ok. 6 passed; 0 failed; 1 ignored; 0 measured; 0 filtered out
+
diff --git a/test-cargo-miri/test.filter.cross-target.stdout.ref b/test-cargo-miri/test.filter.cross-target.stdout.ref
new file mode 100644
index 0000000000..37efb8c3ee
--- /dev/null
+++ b/test-cargo-miri/test.filter.cross-target.stdout.ref
@@ -0,0 +1,11 @@
+
+running 0 tests
+
+test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 1 filtered out
+
+
+running 1 test
+test simple1 ... ok
+
+test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 6 filtered out
+