diff --git a/src/memray/commands/attach.py b/src/memray/commands/attach.py
index 4c2482bed3..55c3bba017 100644
--- a/src/memray/commands/attach.py
+++ b/src/memray/commands/attach.py
@@ -48,6 +48,11 @@ def _get_current_heap_size() -> int:
     return rss_bytes
 
 
+class BareExceptionMessage(Exception):
+    def __repr__(self):
+        return self.args[0]
+
+
 class RepeatingTimer(threading.Thread):
     def __init__(self, interval, function):
         self._interval = interval
@@ -143,6 +148,8 @@ def deactivate_because_timer_elapsed():
 if {mode!r} == "ACTIVATE":
     activate_tracker()
 elif {mode!r} == "DEACTIVATE":
+    if not getattr(memray, "_last_tracker", None):
+        raise BareExceptionMessage("no previous `memray attach` call detected")
     deactivate_last_tracker()
 elif {mode!r} == "UNTIL_HEAP_SIZE":
     track_until_heap_size({heap_size})
diff --git a/tests/integration/test_attach.py b/tests/integration/test_attach.py
index 12a27cf558..724f4ccd91 100644
--- a/tests/integration/test_attach.py
+++ b/tests/integration/test_attach.py
@@ -52,7 +52,7 @@ def baz():
 """
 
 
-def generate_command(method, output, *args):
+def generate_attach_command(method, output, *args):
     cmd = [
         sys.executable,
         "-m",
@@ -72,6 +72,23 @@ def generate_command(method, output, *args):
     return cmd
 
 
+def generate_detach_command(method, *args):
+    cmd = [
+        sys.executable,
+        "-m",
+        "memray",
+        "detach",
+        "--verbose",
+        "--method",
+        method,
+    ]
+
+    if args:
+        cmd.extend(args)
+
+    return cmd
+
+
 def run_process(cmd, wait_for_stderr=False):
     process_stderr = ""
     tracked_process = subprocess.Popen(
@@ -137,7 +154,7 @@ def test_basic_attach(tmp_path, method):
 
     # GIVEN
     output = tmp_path / "test.bin"
-    attach_cmd = generate_command(method, output)
+    attach_cmd = generate_attach_command(method, output)
 
     # WHEN
     run_process(attach_cmd)
@@ -155,7 +172,7 @@ def test_aggregated_attach(tmp_path, method):
 
     # GIVEN
     output = tmp_path / "test.bin"
-    attach_cmd = generate_command(method, output, "--aggregate")
+    attach_cmd = generate_attach_command(method, output, "--aggregate")
 
     # WHEN
     run_process(attach_cmd)
@@ -180,7 +197,7 @@ def test_attach_heap(tmp_path, method):
     # GIVEN
     limit = 50 * 1024 * 1024
     output = tmp_path / "test.bin"
-    attach_cmd = generate_command(method, output, "--heap-limit", str(limit))
+    attach_cmd = generate_attach_command(method, output, "--heap-limit", str(limit))
 
     # WHEN
     process_stderr = run_process(attach_cmd, wait_for_stderr=True)
@@ -197,10 +214,29 @@ def test_attach_time(tmp_path, method):
 
     # GIVEN
     output = tmp_path / "test.bin"
-    attach_cmd = generate_command(method, output, "--duration", "1")
+    attach_cmd = generate_attach_command(method, output, "--duration", "1")
 
     # WHEN
     process_stderr = run_process(attach_cmd, wait_for_stderr=True)
 
     # THEN
     assert "memray: Deactivating tracking: 1 seconds have elapsed" in process_stderr
+
+
+@pytest.mark.parametrize("method", ["lldb", "gdb"])
+def test_detach_without_attach(method):
+    if not debugger_available(method):
+        pytest.skip(f"a supported {method} debugger isn't installed")
+
+    # GIVEN
+    detach_cmd = generate_detach_command(method)
+
+    # WHEN
+    with pytest.raises(subprocess.CalledProcessError) as exc_info:
+        run_process(detach_cmd)
+
+    # THEN
+    assert (
+        "Failed to stop tracking in remote process:"
+        " no previous `memray attach` call detected"
+    ) in exc_info.value.stdout