diff --git a/compiler-rt/lib/asan/asan_activation.cc b/compiler-rt/lib/asan/asan_activation.cc
index 2771ff0f0087..7615164b1adf 100644
--- a/compiler-rt/lib/asan/asan_activation.cc
+++ b/compiler-rt/lib/asan/asan_activation.cc
@@ -57,6 +57,8 @@ void AsanActivate() {
   common_flags()->malloc_context_size =
       asan_deactivated_flags.malloc_context_size;
 
+  ParseExtraActivationFlags();
+
   asan_is_deactivated = false;
   VReport(
       1,
diff --git a/compiler-rt/lib/asan/asan_internal.h b/compiler-rt/lib/asan/asan_internal.h
index 3914fbbd1e93..4dbcae193b09 100644
--- a/compiler-rt/lib/asan/asan_internal.h
+++ b/compiler-rt/lib/asan/asan_internal.h
@@ -87,6 +87,8 @@ void PlatformTSDDtor(void *tsd);
 
 void AppendToErrorMessageBuffer(const char *buffer);
 
+void ParseExtraActivationFlags();
+
 // Platfrom-specific options.
 #if SANITIZER_MAC
 bool PlatformHasDifferentMemcpyAndMemmove();
diff --git a/compiler-rt/lib/asan/asan_rtl.cc b/compiler-rt/lib/asan/asan_rtl.cc
index 2a97ed5954c8..478bbf418497 100644
--- a/compiler-rt/lib/asan/asan_rtl.cc
+++ b/compiler-rt/lib/asan/asan_rtl.cc
@@ -209,6 +209,17 @@ void InitializeFlags(Flags *f, const char *env) {
   }
 }
 
+// Parse flags that may change between startup and activation.
+// On Android they come from a system property.
+// On other platforms this is no-op.
+void ParseExtraActivationFlags() {
+  char buf[100];
+  GetExtraActivationFlags(buf, sizeof(buf));
+  ParseFlagsFromString(flags(), buf);
+  if (buf[0] != '\0')
+    VReport(1, "Extra activation flags: %s\n", buf);
+}
+
 // -------------------------- Globals --------------------- {{{1
 int asan_inited;
 bool asan_init_is_running;
@@ -413,6 +424,10 @@ static void AsanInitInternal() {
   // initialization steps look at flags().
   const char *options = GetEnv("ASAN_OPTIONS");
   InitializeFlags(flags(), options);
+
+  if (!flags()->start_deactivated)
+    ParseExtraActivationFlags();
+
   __sanitizer_set_report_path(common_flags()->log_path);
   __asan_option_detect_stack_use_after_return =
       flags()->detect_stack_use_after_return;
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common.h b/compiler-rt/lib/sanitizer_common/sanitizer_common.h
index a5c8df0c30ef..e6de486bb695 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common.h
@@ -506,8 +506,10 @@ F IndirectExternCall(F f) {
 
 #if SANITIZER_ANDROID
 void AndroidLogWrite(const char *buffer);
+void GetExtraActivationFlags(char *buf, uptr size);
 #else
 INLINE void AndroidLogWrite(const char *buffer_unused) {}
+INLINE void GetExtraActivationFlags(char *buf, uptr size) { *buf = '\0'; }
 #endif
 }  // namespace __sanitizer
 
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc b/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc
index 2a954772bef0..73a35ca23378 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_linux.cc
@@ -51,6 +51,7 @@
 
 #if SANITIZER_ANDROID
 #include <android/log.h>
+#include <sys/system_properties.h>
 #endif
 
 // <linux/time.h>
@@ -697,6 +698,11 @@ uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
 void AndroidLogWrite(const char *buffer) {
   __android_log_write(ANDROID_LOG_INFO, NULL, buffer);
 }
+
+void GetExtraActivationFlags(char *buf, uptr size) {
+  CHECK(size > PROP_VALUE_MAX);
+  __system_property_get("asan.options", buf);
+}
 #endif
 
 bool IsDeadlySignal(int signum) {