diff --git a/crypto/rand/fork_detect_test.cc b/crypto/rand/fork_detect_test.cc
index 15f3fc0..b219f89 100644
--- a/crypto/rand/fork_detect_test.cc
+++ b/crypto/rand/fork_detect_test.cc
@@ -39,6 +39,7 @@
 
 #if defined(OPENSSL_LINUX)
 #include <stdlib.h>
+#include <sys/mman.h>
 #include <sys/utsname.h>
 #endif
 
@@ -165,6 +166,27 @@
         }
       }
     }
+
+    // Qemu claims support for any unsupported MADV_ flags, so the production
+    // code currently always disables reliance on MADV_WIPEONFORK when on qemu.
+    // Detect this situation explicitly here too so the test does not fail.
+    long page_size = sysconf(_SC_PAGESIZE);
+    ASSERT_GT(page_size, 0) << "System does not provide its page size. Expect "
+                               "reduced performance, but no security impact.";
+    void *addr =
+        mmap(nullptr, static_cast<size_t>(page_size), PROT_READ | PROT_WRITE,
+             MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+    ASSERT_NE(addr, nullptr)
+        << "mmap() cannot produce a private anonymous mapping. Expect reduced "
+           "performance, but no security impact.";
+    int madvise_broken = madvise(addr, page_size, -1) == 0;
+    munmap(addr, page_size);
+    if (madvise_broken) {
+      GTEST_SKIP()
+          << "System claims support for madvise() with invalid flags (typical "
+             "of qemu), which means return values are unreliable. Expect even "
+             "more reduced performance at runtime.\n";
+    }
   }
 #endif
   EXPECT_NE(start, uint64_t{0})