diff --git a/src/validation.cpp b/src/validation.cpp
index 9c0ffd44e0..9f99b5b4ec 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1888,6 +1888,12 @@ static unsigned int GetBlockScriptFlags(const CBlockIndex* pindex, const Consens
         flags |= SCRIPT_VERIFY_P2SH;
     }
 
+    // Enforce WITNESS rules whenever P2SH is in effect (and the segwit
+    // deployment is defined).
+    if (flags & SCRIPT_VERIFY_P2SH && IsScriptWitnessEnabled(consensusparams)) {
+        flags |= SCRIPT_VERIFY_WITNESS;
+    }
+
     // Start enforcing the DERSIG (BIP66) rule
     if (pindex->nHeight >= consensusparams.BIP66Height) {
         flags |= SCRIPT_VERIFY_DERSIG;