diff --git a/src/init.cpp b/src/init.cpp
index 24659de3df0..6f44ed6c3d6 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -1613,6 +1613,24 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
         return false;
     }
 
+    int chain_active_height = WITH_LOCK(cs_main, return chainman.ActiveChain().Height());
+
+    // On first startup, warn on low block storage space
+    if (!fReindex && !fReindexChainState && chain_active_height <= 1) {
+        uint64_t additional_bytes_needed = fPruneMode ? nPruneTarget
+            : chainparams.AssumedBlockchainSize() * 1024 * 1024 * 1024;
+
+        if (!CheckDiskSpace(args.GetBlocksDirPath(), additional_bytes_needed)) {
+            InitWarning(strprintf(_(
+                    "Disk space for %s may not accommodate the block files. " \
+                    "Approximately %u GB of data will be stored in this directory."
+                ),
+                fs::quoted(fs::PathToString(args.GetBlocksDirPath())),
+                chainparams.AssumedBlockchainSize()
+            ));
+        }
+    }
+
     // Either install a handler to notify us when genesis activates, or set fHaveGenesis directly.
     // No locking, as this happens before any background thread is started.
     boost::signals2::connection block_notify_genesis_wait_connection;
@@ -1662,8 +1680,6 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
 
     // ********************************************************* Step 12: start node
 
-    int chain_active_height;
-
     //// debug print
     {
         LOCK(cs_main);
diff --git a/test/functional/p2p_dos_header_tree.py b/test/functional/p2p_dos_header_tree.py
index 7e269945118..1f904644fc6 100755
--- a/test/functional/p2p_dos_header_tree.py
+++ b/test/functional/p2p_dos_header_tree.py
@@ -22,7 +22,7 @@ class RejectLowDifficultyHeadersTest(BitcoinTestFramework):
         self.setup_clean_chain = True
         self.chain = 'testnet3'  # Use testnet chain because it has an early checkpoint
         self.num_nodes = 2
-        self.extra_args = [["-minimumchainwork=0x0"], ["-minimumchainwork=0x0"]]
+        self.extra_args = [["-minimumchainwork=0x0", '-prune=550']] * self.num_nodes
 
     def add_options(self, parser):
         parser.add_argument(
@@ -63,7 +63,7 @@ class RejectLowDifficultyHeadersTest(BitcoinTestFramework):
 
         self.log.info("Feed all fork headers (succeeds without checkpoint)")
         # On node 0 it succeeds because checkpoints are disabled
-        self.restart_node(0, extra_args=['-nocheckpoints', "-minimumchainwork=0x0"])
+        self.restart_node(0, extra_args=['-nocheckpoints', "-minimumchainwork=0x0", '-prune=550'])
         peer_no_checkpoint = self.nodes[0].add_p2p_connection(P2PInterface())
         peer_no_checkpoint.send_and_ping(msg_headers(self.headers_fork))
         assert {
diff --git a/test/functional/wallet_crosschain.py b/test/functional/wallet_crosschain.py
index b6d0c87985f..c0047542ed3 100755
--- a/test/functional/wallet_crosschain.py
+++ b/test/functional/wallet_crosschain.py
@@ -21,7 +21,7 @@ class WalletCrossChain(BitcoinTestFramework):
 
         # Switch node 1 to testnet before starting it.
         self.nodes[1].chain = 'testnet3'
-        self.nodes[1].extra_args = ['-maxconnections=0'] # disable testnet sync
+        self.nodes[1].extra_args = ['-maxconnections=0', '-prune=550'] # disable testnet sync
         with open(self.nodes[1].bitcoinconf, 'r', encoding='utf8') as conf:
             conf_data = conf.read()
         with open (self.nodes[1].bitcoinconf, 'w', encoding='utf8') as conf:
@@ -51,7 +51,7 @@ class WalletCrossChain(BitcoinTestFramework):
         if not self.options.descriptors:
             self.log.info("Override cross-chain wallet load protection")
             self.stop_nodes()
-            self.start_nodes([['-walletcrosschain']] * self.num_nodes)
+            self.start_nodes([['-walletcrosschain', '-prune=550']] * self.num_nodes)
             self.nodes[0].loadwallet(node1_wallet)
             self.nodes[1].loadwallet(node0_wallet)