diff --git a/compiler-rt/lib/asan/asan_activation.cc b/compiler-rt/lib/asan/asan_activation.cc
index 010cf319bda2..0aca1cb4e86d 100644
--- a/compiler-rt/lib/asan/asan_activation.cc
+++ b/compiler-rt/lib/asan/asan_activation.cc
@@ -39,6 +39,12 @@ static struct AsanDeactivatedFlags {
     // Check if activation flags need to be overriden.
     // FIXME: Add diagnostic to check that activation flags string doesn't
     // contain any other flags.
+    if (const char *env = GetEnv("ASAN_ACTIVATION_OPTIONS")) {
+      cf.ParseFromString(env);
+      ParseFlagsFromString(&f, env);
+    }
+
+    // Override from getprop asan.options.
     char buf[100];
     GetExtraActivationFlags(buf, sizeof(buf));
     cf.ParseFromString(buf);
diff --git a/compiler-rt/test/asan/TestCases/Posix/start-deactivated.cc b/compiler-rt/test/asan/TestCases/Posix/start-deactivated.cc
index 2280e2af03f3..e5e83066b278 100644
--- a/compiler-rt/test/asan/TestCases/Posix/start-deactivated.cc
+++ b/compiler-rt/test/asan/TestCases/Posix/start-deactivated.cc
@@ -5,11 +5,13 @@
 // RUN: %clangxx_asan -O0 -DSHARED_LIB %s -fPIC -shared -o %t-so.so
 // RUN: %clangxx -O0 %s -c -o %t.o
 // RUN: %clangxx_asan -O0 %t.o %libdl -o %t
-// RUN: ASAN_OPTIONS=start_deactivated=1 not %run %t 2>&1 | FileCheck %s
+// RUN: ASAN_OPTIONS=start_deactivated=1,allocator_may_return_null=0 \
+// RUN:   ASAN_ACTIVATION_OPTIONS=allocator_may_return_null=1 not %run %t 2>&1 | FileCheck %s
 // XFAIL: arm-linux-gnueabi
 // XFAIL: armv7l-unknown-linux-gnueabihf
 
 #if !defined(SHARED_LIB)
+#include <assert.h>
 #include <dlfcn.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -43,12 +45,18 @@ int main(int argc, char *argv[]) {
   test_malloc_shadow();
   // CHECK: =5=
 
+  // After this line ASan is activated and starts detecting errors.
   void *fn = dlsym(dso, "do_another_bad_thing");
   if (!fn) {
     fprintf(stderr, "dlsym failed: %s\n", dlerror());
     return 1;
   }
 
+  // Test that ASAN_ACTIVATION_OPTIONS=allocator_may_return_null=1 has effect.
+  void *p = malloc((unsigned long)-2);
+  assert(!p);
+  // CHECK: WARNING: AddressSanitizer failed to allocate 0xfff{{.*}} bytes
+
   ((Fn)fn)();
   // CHECK: AddressSanitizer: heap-buffer-overflow
   // CHECK: READ of size 1