diff --git a/doc/release-notes-5772.md b/doc/release-notes-5772.md
new file mode 100644
index 000000000000..e771ebe780e9
--- /dev/null
+++ b/doc/release-notes-5772.md
@@ -0,0 +1,4 @@
+RPC changes
+-----------
+
+`quorum getdata` RPC will no longer allow `proTxHash` to be specified when `dataMask` is set to `1`.
diff --git a/src/rpc/quorums.cpp b/src/rpc/quorums.cpp
index 5c6f54414fa2..c209a8e96fbd 100644
--- a/src/rpc/quorums.cpp
+++ b/src/rpc/quorums.cpp
@@ -813,8 +813,8 @@ static RPCHelpMan quorum_getdata()
     uint16_t nDataMask = static_cast<uint16_t>(ParseInt32V(request.params[3], "dataMask"));
     uint256 proTxHash;
 
-    // Check if request wants ENCRYPTED_CONTRIBUTIONS data
     if (nDataMask & llmq::CQuorumDataRequest::ENCRYPTED_CONTRIBUTIONS) {
+        // Require proTxHash if request wants ENCRYPTED_CONTRIBUTIONS data
         if (!request.params[4].isNull()) {
             proTxHash = ParseHashV(request.params[4], "proTxHash");
             if (proTxHash.IsNull()) {
@@ -823,6 +823,9 @@ static RPCHelpMan quorum_getdata()
         } else {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "proTxHash missing");
         }
+    } else if (!request.params[4].isNull()) {
+        // Require no proTxHash otherwise
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Should not specify proTxHash");
     }
 
     const auto quorum = llmq_ctx.qman->GetQuorum(llmqType, quorumHash);
diff --git a/test/functional/p2p_quorum_data.py b/test/functional/p2p_quorum_data.py
index a85616ad8aa2..4f0182e6b959 100755
--- a/test/functional/p2p_quorum_data.py
+++ b/test/functional/p2p_quorum_data.py
@@ -395,6 +395,8 @@ def test_watchquorums():
 
         def test_rpc_quorum_getdata_protx_hash():
             self.log.info("Test optional proTxHash of `quorum getdata`")
+            assert_raises_rpc_error(-8, "Should not specify proTxHash",
+                                    mn1.get_node(self).quorum, "getdata", 0, 100, quorum_hash, 0x01, mn1.proTxHash)
             assert_raises_rpc_error(-8, "proTxHash missing",
                                     mn1.get_node(self).quorum, "getdata", 0, 100, quorum_hash, 0x02)
             assert_raises_rpc_error(-8, "proTxHash invalid",