diff --git a/src/evo/specialtx_validation.cpp b/src/evo/specialtx_validation.cpp
index 0c3f1ee6fbb2db..6491fbb37dbf10 100644
--- a/src/evo/specialtx_validation.cpp
+++ b/src/evo/specialtx_validation.cpp
@@ -244,6 +244,9 @@ static bool CheckProRegTx(const CTransaction& tx, const CBlockIndex* pindexPrev,
             if (pl.shieldCollateral.bindingSig.size() != (*txMut.sapData).bindingSig.size()) {
                 return state.DoS(100, false, REJECT_INVALID, "bad-protx-bindingSig-len");
             }
+            if (pl.shieldCollateral.output.nValue != Params().GetConsensus().nMNCollateralAmt) {
+                return state.DoS(100, false, REJECT_INVALID, "bad-protx-proofCollateralOutput-amt");
+            }
             std::copy(pl.shieldCollateral.bindingSig.begin(), pl.shieldCollateral.bindingSig.end(), (*txMut.sapData).bindingSig.begin());
 
             // Check that the proof is valid