--- a/xpcom/tests/TestDeadlockDetectorScalability.cpp
+++ b/xpcom/tests/TestDeadlockDetectorScalability.cpp
@@ -170,17 +170,18 @@ main(int argc, char** argv)
 #else
     if (NS_FAILED(LengthNDepChain(1 << 14))) // 16K
         rv = 1;
 #endif
 
 #ifndef DD_TEST2
     puts("Skipping not-requested OneLockNDeps() test");
 #else
-    if (NS_FAILED(OneLockNDeps(1 << 14, 100))) // 16k
+    // NB: Using a larger test size to stress our traversal logic.
+    if (NS_FAILED(OneLockNDeps(1 << 17, 100))) // 131k
         rv = 1;
 #endif
 
 #ifndef DD_TEST3
     puts("Skipping not-requested MaxDepsNsq() test");
 #else
     if (NS_FAILED(MaxDepsNsq(1 << 10, 10))) // 1k
         rv = 1;