diff --git a/tests/map_test.cpp b/tests/map_test.cpp
index 7c40b73..149a704 100644
--- a/tests/map_test.cpp
+++ b/tests/map_test.cpp
@@ -31,11 +31,19 @@
 
 TEST(ScudoMapTest, MapUnmap) {
   const scudo::uptr Size = 4 * scudo::getPageSizeCached();
-  void *P = scudo::map(nullptr, Size, MappingName, 0, nullptr);
-  EXPECT_NE(P, nullptr);
-  memset(P, 0xaa, Size);
-  scudo::unmap(P, Size, 0, nullptr);
-  EXPECT_DEATH(memset(P, 0xbb, Size), "");
+  EXPECT_DEATH(
+      {
+        // Repeat few time to avoid missing crash if it's mmaped by unrelated
+        // code.
+        for (int i = 0; i < 10; ++i) {
+          void *P = scudo::map(nullptr, Size, MappingName, 0, nullptr);
+          if (!P)
+            continue;
+          scudo::unmap(P, Size, 0, nullptr);
+          memset(P, 0xbb, Size);
+        }
+      },
+      "");
 }
 
 TEST(ScudoMapTest, MapWithGuardUnmap) {
diff --git a/tests/secondary_test.cpp b/tests/secondary_test.cpp
index 9dcf52d..d5d1599 100644
--- a/tests/secondary_test.cpp
+++ b/tests/secondary_test.cpp
@@ -39,9 +39,20 @@
 // the test on arm32 until we can debug it further.
 #ifndef __arm__
   // If the Secondary can't cache that pointer, it will be unmapped.
-  if (!L->canCache(Size))
-    EXPECT_DEATH(memset(P, 'A', Size), "");
+  if (!L->canCache(Size)) {
+    EXPECT_DEATH(
+        {
+          // Repeat few time to avoid missing crash if it's mmaped by unrelated
+          // code.
+          for (int i = 0; i < 10; ++i) {
+            P = L->allocate(scudo::Options{}, Size);
+            L->deallocate(scudo::Options{}, P);
+            memset(P, 'A', Size);
+          }
+        },
+        "");
 #endif // __arm__
+  }
 
   const scudo::uptr Align = 1U << 16;
   P = L->allocate(scudo::Options{}, Size + Align, Align);