diff --git a/core/optionsx.h b/core/optionsx.h
index 75ff5325711..d97d9e93f19 100644
--- a/core/optionsx.h
+++ b/core/optionsx.h
@@ -3200,6 +3200,8 @@ OPTION(bool, multi_thread_exit,
        "do not guarantee that process exit event callback is invoked single-threaded")
 OPTION(bool, skip_thread_exit_at_exit, "skip thread exit events at process exit")
 #endif
+OPTION(bool, ignore_takeover_timeout,
+       "ignore timeouts trying to take over one or more threads when initializing")
 
 #ifdef EXPOSE_INTERNAL_OPTIONS
 OPTION_NAME(bool, optimize, " synthethic", "set if ANY opts are on")
diff --git a/core/unix/os.c b/core/unix/os.c
index 0610cfb2e20..12e451af544 100644
--- a/core/unix/os.c
+++ b/core/unix/os.c
@@ -10056,7 +10056,7 @@ os_take_over_all_unknown_threads(dcontext_t *dcontext)
     uint i;
     uint num_threads;
     thread_id_t *tids;
-    uint threads_to_signal = 0;
+    uint threads_to_signal = 0, threads_timed_out = 0;
 
     /* We do not want to re-takeover a thread that's in between notifying us on
      * the last call to this routine and getting onto the all_threads list as
@@ -10155,6 +10155,8 @@ os_take_over_all_unknown_threads(dcontext_t *dcontext)
                        get_application_pid());
             }
             static const int wait_ms = 25;
+            static const int max_attempts = 16;
+            int attempts = 0;
             while (!wait_for_event(records[i].event, wait_ms)) {
                 /* The thread may have exited (i#2601).  We assume no tid re-use. */
                 char task[64];
@@ -10164,6 +10166,22 @@ os_take_over_all_unknown_threads(dcontext_t *dcontext)
                     SYSLOG_INTERNAL_WARNING_ONCE("thread exited while attaching");
                     break;
                 }
+                if (++attempts > max_attempts) {
+                    if (DYNAMO_OPTION(ignore_takeover_timeout)) {
+                        SYSLOG(SYSLOG_VERBOSE, THREAD_TAKEOVER_TIMED_OUT, 3,
+                               get_application_name(), get_application_pid(),
+                               "Continuing since -ignore_takeover_timeout is set.");
+                        ++threads_timed_out;
+                    } else {
+                        SYSLOG(SYSLOG_VERBOSE, THREAD_TAKEOVER_TIMED_OUT, 3,
+                               get_application_name(), get_application_pid(),
+                               "Aborting. Use -ignore_takeover_timeout to ignore.");
+                        REPORT_FATAL_ERROR_AND_EXIT(FAILED_TO_TAKE_OVER_THREADS, 2,
+                                                    get_application_name(),
+                                                    get_application_pid());
+                    }
+                    break;
+                }
                 /* Else try again. */
             }
         }
@@ -10187,7 +10205,8 @@ os_take_over_all_unknown_threads(dcontext_t *dcontext)
     d_r_mutex_unlock(&thread_initexit_lock);
     HEAP_ARRAY_FREE(dcontext, tids, thread_id_t, num_threads, ACCT_THREAD_MGT, PROTECTED);
 
-    return threads_to_signal > 0;
+    ASSERT(threads_to_signal >= threads_timed_out);
+    return (threads_to_signal - threads_timed_out) > 0;
 }
 
 bool
diff --git a/core/win32/events.mc b/core/win32/events.mc
index d46d62b0274..cad74db2ac2 100644
--- a/core/win32/events.mc
+++ b/core/win32/events.mc
@@ -644,6 +644,14 @@ Language=English
 Application %1!s! (%2!s!). Failed to take over all threads after multiple attempts.
 .
 
+MessageId =
+Severity = Error
+Facility = DRCore
+SymbolicName = MSG_THREAD_TAKEOVER_TIMED_OUT
+Language=English
+Application %1!s! (%2!s!). Timed out attempting to take over one or more threads. %3!s!
+.
+
 ;#ifdef UNIX
 MessageId =
 Severity = Error