diff --git a/src/sentry_sync.h b/src/sentry_sync.h
index 66309886a..1a9c48a6c 100644
--- a/src/sentry_sync.h
+++ b/src/sentry_sync.h
@@ -135,6 +135,22 @@ WakeConditionVariable_PREVISTA(PCONDITION_VARIABLE_PREVISTA ConditionVariable)
         ConditionVariable->ContinueEvent, INFINITE, FALSE);
 }
 
+inline void
+WakeAllConditionVariable_PREVISTA(
+    PCONDITION_VARIABLE_PREVISTA ConditionVariable)
+{
+    if (!ConditionVariable) {
+        return;
+    }
+
+    LONG waiters = InterlockedCompareExchange(
+        (volatile LONG *)&ConditionVariable->Waiters, 0, 0);
+    if (waiters > 0) {
+        ConditionVariable->Target = -1;
+        ReleaseSemaphore(ConditionVariable->Semaphore, waiters, NULL);
+    }
+}
+
 #    endif /* _WIN32_WINNT < 0x0600 */
 
 struct sentry__winmutex_s {
@@ -195,6 +211,7 @@ typedef CONDITION_VARIABLE_PREVISTA sentry_cond_t;
 #        define sentry__cond_init(CondVar)                                     \
             InitializeConditionVariable_PREVISTA(CondVar)
 #        define sentry__cond_wake WakeConditionVariable_PREVISTA
+#        define sentry__cond_wake_all WakeAllConditionVariable_PREVISTA
 #        define sentry__cond_wait_timeout(CondVar, Lock, Timeout)              \
             SleepConditionVariableCS_PREVISTA(                                 \
                 CondVar, &(Lock)->critical_section, Timeout)
@@ -202,6 +219,7 @@ typedef CONDITION_VARIABLE_PREVISTA sentry_cond_t;
 typedef CONDITION_VARIABLE sentry_cond_t;
 #        define sentry__cond_init(CondVar) InitializeConditionVariable(CondVar)
 #        define sentry__cond_wake WakeConditionVariable
+#        define sentry__cond_wake_all WakeAllConditionVariable
 #        define sentry__cond_wait_timeout(CondVar, Lock, Timeout)              \
             SleepConditionVariableCS(                                          \
                 CondVar, &(Lock)->critical_section, Timeout)
@@ -344,6 +362,7 @@ typedef pthread_cond_t sentry_cond_t;
             }                                                                  \
         } while (0)
 #    define sentry__cond_wake pthread_cond_signal
+#    define sentry__cond_wake_all pthread_cond_broadcast
 #    define sentry__thread_init(ThreadId)                                      \
         memset(ThreadId, 0, sizeof(sentry_threadid_t))
 #    define sentry__thread_spawn(ThreadId, Func, Data)                         \
diff --git a/tests/unit/test_sync.c b/tests/unit/test_sync.c
index 98c5eeef9..cfc2a03fc 100644
--- a/tests/unit/test_sync.c
+++ b/tests/unit/test_sync.c
@@ -581,6 +581,72 @@ SENTRY_TEST(bgworker_delayed_shutdown)
     sentry__bgworker_decref(bgw);
 }
 
+#define COND_WAKE_ALL_THREADS 2
+
+struct cond_wake_all_state {
+    sentry_mutex_t mutex;
+    sentry_cond_t waiting_cond;
+    sentry_cond_t ready_cond;
+    volatile long waiting;
+    volatile long woke;
+    bool ready;
+};
+
+SENTRY_THREAD_FN
+cond_wake_all_thread(void *data)
+{
+    struct cond_wake_all_state *state = data;
+
+    sentry__mutex_lock(&state->mutex);
+    sentry__atomic_fetch_and_add(&state->waiting, 1);
+    sentry__cond_wake(&state->waiting_cond);
+    while (!state->ready) {
+        sentry__cond_wait(&state->ready_cond, &state->mutex);
+    }
+    sentry__atomic_fetch_and_add(&state->woke, 1);
+    sentry__mutex_unlock(&state->mutex);
+
+    return 0;
+}
+
+SENTRY_TEST(cond_wake_all)
+{
+    struct cond_wake_all_state state = { 0 };
+    sentry_threadid_t threads[COND_WAKE_ALL_THREADS];
+
+    sentry__mutex_init(&state.mutex);
+    sentry__cond_init(&state.waiting_cond);
+    sentry__cond_init(&state.ready_cond);
+
+    for (int i = 0; i < COND_WAKE_ALL_THREADS; i++) {
+        sentry__thread_init(&threads[i]);
+        TEST_ASSERT(
+            sentry__thread_spawn(&threads[i], cond_wake_all_thread, &state)
+            == 0);
+    }
+
+    sentry__mutex_lock(&state.mutex);
+    while (sentry__atomic_fetch(&state.waiting) < COND_WAKE_ALL_THREADS) {
+        sentry__cond_wait(&state.waiting_cond, &state.mutex);
+    }
+    state.ready = true;
+    sentry__cond_wake_all(&state.ready_cond);
+    sentry__mutex_unlock(&state.mutex);
+
+    for (int i = 0; i < COND_WAKE_ALL_THREADS; i++) {
+        sentry__thread_join(threads[i]);
+    }
+
+    TEST_CHECK_INT_EQUAL(
+        sentry__atomic_fetch(&state.woke), COND_WAKE_ALL_THREADS);
+
+#ifndef SENTRY_PLATFORM_WINDOWS
+    pthread_cond_destroy(&state.ready_cond);
+    pthread_cond_destroy(&state.waiting_cond);
+#endif
+    sentry__mutex_free(&state.mutex);
+}
+
 SENTRY_TEST(cond_wait_timeout_overflow)
 {
 #if !(defined(SENTRY_PLATFORM_MACOS)                                           \
diff --git a/tests/unit/tests.inc b/tests/unit/tests.inc
index 5f0265802..e51c7fff3 100644
--- a/tests/unit/tests.inc
+++ b/tests/unit/tests.inc
@@ -102,6 +102,7 @@ XX(client_report_save_raw_envelope)
 XX(concurrent_init)
 XX(concurrent_uninit)
 XX(cond_wait_timeout_overflow)
+XX(cond_wake_all)
 XX(continuation_no_baggage_uses_sdk_dsc)
 XX(count_sampled_events)
 XX(crash_context_handler_path_propagation)