diff --git a/llvm/lib/Transforms/IPO/SampleProfile.cpp b/llvm/lib/Transforms/IPO/SampleProfile.cpp
--- a/llvm/lib/Transforms/IPO/SampleProfile.cpp
+++ b/llvm/lib/Transforms/IPO/SampleProfile.cpp
@@ -2048,6 +2048,12 @@
         UsePreInlinerDecision = true;
     }
 
+    // Enable stale profile matching by default for CSSPGO.
+    if (Reader->profileIsProbeBased()) {
+      if (!SalvageStaleProfile.getNumOccurrences())
+        SalvageStaleProfile = true;
+    }
+
     if (!Reader->profileIsCS()) {
       // Non-CS profile should be fine without a function size budget for the
       // inliner since the contexts in the profile are either all from inlining