diff --git a/include/vis/vis.hh b/include/vis/vis.hh
index 10285d06..7bc0091c 100644
--- a/include/vis/vis.hh
+++ b/include/vis/vis.hh
@@ -153,13 +153,9 @@ inline float viswinding_t::distFromPortal(visportal_t &p)
     return mindist;
 }
 
-/* Increased MAX_PORTALS_ON_LEAF from 128 */
-constexpr size_t MAX_PORTALS_ON_LEAF = 512;
-
 struct leaf_t
 {
-    int numportals;
-    visportal_t *portals[MAX_PORTALS_ON_LEAF];
+    std::vector<visportal_t *> portals;
 };
 
 constexpr size_t MAX_SEPARATORS = MAX_WINDING;
diff --git a/vis/flow.cc b/vis/flow.cc
index 69a2a0b7..f46c724b 100644
--- a/vis/flow.cc
+++ b/vis/flow.cc
@@ -131,10 +131,9 @@ static int CheckStack(leaf_t *leaf, threaddata_t *thread)
 static void RecursiveLeafFlow(int leafnum, threaddata_t *thread, pstack_t &prevstack)
 {
     pstack_t stack;
-    visportal_t *p;
     qplane3d backplane;
     leaf_t *leaf;
-    int i, j, err, numblocks;
+    int j, err, numblocks;
 
     ++thread->stats.c_chains;
 
@@ -165,7 +164,7 @@ static void RecursiveLeafFlow(int leafnum, threaddata_t *thread, pstack_t &prevs
     stack.numseparators[0] = 0;
     stack.numseparators[1] = 0;
 
-    for (i = 0; i < STACK_WINDINGS; i++)
+    for (int i = 0; i < STACK_WINDINGS; i++)
         stack.windings_used[i] = false;
 
     leafbits_t local(portalleafs);
@@ -175,9 +174,7 @@ static void RecursiveLeafFlow(int leafnum, threaddata_t *thread, pstack_t &prevs
     auto vis = thread->leafvis.data();
 
     // check all portals for flowing into other leafs
-    for (i = 0; i < leaf->numportals; i++) {
-        p = leaf->portals[i];
-
+    for (visportal_t *p : leaf->portals) {
         if (!(*prevstack.mightsee)[p->leaf]) {
             thread->stats.c_leafskip++;
             continue; // can't possibly see it
@@ -363,9 +360,7 @@ static void SimpleFlood(visportal_t &srcportal, int leafnum, const leafbits_t &p
     srcportal.nummightsee++;
 
     leaf_t &leaf = leafs[leafnum];
-    for (size_t i = 0; i < leaf.numportals; i++) {
-        const visportal_t *p = leaf.portals[i];
-
+    for (const visportal_t *p : leaf.portals) {
         if (portalsee[p - portals.data()]) {
             SimpleFlood(srcportal, p->leaf, portalsee);
         }
diff --git a/vis/vis.cc b/vis/vis.cc
index 4a3d0430..4a5a001d 100644
--- a/vis/vis.cc
+++ b/vis/vis.cc
@@ -269,8 +269,7 @@ visportal_t *GetNextPortal(void)
 static void UpdateMightsee(visstats_t &stats, const leaf_t &source, const leaf_t &dest)
 {
     size_t leafnum = &dest - leafs.data();
-    for (size_t i = 0; i < source.numportals; i++) {
-        visportal_t *p = source.portals[i];
+    for (visportal_t *p : source.portals) {
         if (p->status != pstat_none) {
             continue;
         }
@@ -303,7 +302,7 @@ static void PortalCompleted(visstats_t &stats, visportal_t *completed)
      * mightsee during the full vis so far.
      */
     const leaf_t &myleaf = leafs[completed->leaf];
-    for (int i = 0; i < myleaf.numportals; i++) {
+    for (int i = 0; i < myleaf.portals.size(); i++) {
         const visportal_t *p = myleaf.portals[i];
         if (p->status != pstat_done)
             continue;
@@ -320,7 +319,7 @@ static void PortalCompleted(visstats_t &stats, visportal_t *completed)
              * If any of these changed bits are still visible from another
              * portal, we can't update yet.
              */
-            for (int k = 0; k < myleaf.numportals; k++) {
+            for (int k = 0; k < myleaf.portals.size(); k++) {
                 if (k == i)
                     continue;
                 const visportal_t *p2 = myleaf.portals[k];
@@ -398,8 +397,7 @@ static void ClusterFlow(int clusternum, leafbits_t &buffer, mbsp_t *bsp)
      */
     leaf_t *leaf = &leafs[clusternum];
     int numblocks = (portalleafs + leafbits_t::mask) >> leafbits_t::shift;
-    for (int i = 0; i < leaf->numportals; i++) {
-        const visportal_t *p = leaf->portals[i];
+    for (const visportal_t *p : leaf->portals) {
         if (p->status != pstat_done)
             FError("portal not done");
         for (int j = 0; j < numblocks; j++)
@@ -644,10 +642,7 @@ static void LoadPortals(const fs::path &name, mbsp_t *bsp)
 
             // create forward portal
             auto &l = leafs[sourceportal.leafnums[0]];
-            if (l.numportals == MAX_PORTALS_ON_LEAF)
-                FError("Leaf with too many portals");
-            l.portals[l.numportals] = &p;
-            l.numportals++;
+            l.portals.push_back(&p);
 
             p.plane = -plane;
             p.leaf = sourceportal.leafnums[1];
@@ -658,10 +653,7 @@ static void LoadPortals(const fs::path &name, mbsp_t *bsp)
             auto &p = *dest_portal_it;
             // create backwards portal
             auto &l = leafs[sourceportal.leafnums[1]];
-            if (l.numportals == MAX_PORTALS_ON_LEAF)
-                FError("Leaf with too many portals");
-            l.portals[l.numportals] = &p;
-            l.numportals++;
+            l.portals.push_back(&p);
 
             // Create a reverse winding
             const auto flipped = sourceportal.winding.flip();