diff --git a/src/main/java/net/openhft/chronicle/hash/impl/CompactOffHeapLinearHashTable.java b/src/main/java/net/openhft/chronicle/hash/impl/CompactOffHeapLinearHashTable.java
index 88e52a532..b2a50bfcc 100644
--- a/src/main/java/net/openhft/chronicle/hash/impl/CompactOffHeapLinearHashTable.java
+++ b/src/main/java/net/openhft/chronicle/hash/impl/CompactOffHeapLinearHashTable.java
@@ -26,6 +26,7 @@ public abstract class CompactOffHeapLinearHashTable {
     // to fit 64 bits per slot.
     public static final int MAX_TIER_CHUNKS = 1 << 30;
     public static final int MAX_TIER_ENTRIES = 1 << 29;
+    public static final double MAX_LOAD_FACTOR = .2/.3;
 
 
     public static int valueBits(long actualChunksPerSegment) {
@@ -57,7 +58,7 @@ public abstract class CompactOffHeapLinearHashTable {
         if (entriesPerSegment < 0L)
             throw new IllegalArgumentException("entriesPerSegment should be positive");
         long capacity = Maths.nextPower2(entriesPerSegment, 64L);
-        if (((double) entriesPerSegment) / (double) capacity > 2./3.) {
+        if (((double) entriesPerSegment) / (double) capacity > MAX_LOAD_FACTOR) {
             // hash lookup shouldn't be too dense
             capacity <<= 1L;
         }
diff --git a/src/main/java/net/openhft/chronicle/hash/impl/VanillaChronicleHash.java b/src/main/java/net/openhft/chronicle/hash/impl/VanillaChronicleHash.java
index fdae95a00..0cd23670a 100644
--- a/src/main/java/net/openhft/chronicle/hash/impl/VanillaChronicleHash.java
+++ b/src/main/java/net/openhft/chronicle/hash/impl/VanillaChronicleHash.java
@@ -106,6 +106,7 @@ public abstract class VanillaChronicleHash<K,
     public int tierHashLookupKeyBits;
     public int tierHashLookupEntrySize;
     public long tierHashLookupCapacity;
+    public long maxEntriesPerHashLookup;
     long tierHashLookupInnerSize;
     public long tierHashLookupOuterSize;
 
@@ -194,6 +195,7 @@ public abstract class VanillaChronicleHash<K,
                     "but hash lookup slot is " + tierHashLookupEntrySize);
         }
         tierHashLookupCapacity = CompactOffHeapLinearHashTable.capacityFor(entriesPerSegment);
+        maxEntriesPerHashLookup = (long) (tierHashLookupCapacity * MAX_LOAD_FACTOR);
         tierHashLookupInnerSize = tierHashLookupCapacity * tierHashLookupEntrySize;
         tierHashLookupOuterSize = CACHE_LINES.align(tierHashLookupInnerSize, BYTES);
 
@@ -255,6 +257,7 @@ public abstract class VanillaChronicleHash<K,
         tierHashLookupKeyBits = wireIn.read(() -> "tierHashLookupKeyBits").int32();
         tierHashLookupEntrySize = wireIn.read(() -> "tierHashLookupEntrySize").int32();
         tierHashLookupCapacity = wireIn.read(() -> "tierHashLookupCapacity").int64();
+        maxEntriesPerHashLookup = wireIn.read(() -> "maxEntriesPerHashLookup").int64();
         tierHashLookupInnerSize = wireIn.read(() -> "tierHashLookupInnerSize").int64();
         tierHashLookupOuterSize = wireIn.read(() -> "tierHashLookupOuterSize").int64();
 
@@ -300,6 +303,7 @@ public abstract class VanillaChronicleHash<K,
         wireOut.write(() -> "tierHashLookupKeyBits").int32(tierHashLookupKeyBits);
         wireOut.write(() -> "tierHashLookupEntrySize").int32(tierHashLookupEntrySize);
         wireOut.write(() -> "tierHashLookupCapacity").int64(tierHashLookupCapacity);
+        wireOut.write(() -> "maxEntriesPerHashLookup").int64(maxEntriesPerHashLookup);
         wireOut.write(() -> "tierHashLookupInnerSize").int64(tierHashLookupInnerSize);
         wireOut.write(() -> "tierHashLookupOuterSize").int64(tierHashLookupOuterSize);
 
diff --git a/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/SegmentStages.java b/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/SegmentStages.java
index a19cf91fc..42acc754c 100644
--- a/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/SegmentStages.java
+++ b/src/main/java/net/openhft/chronicle/hash/impl/stage/entry/SegmentStages.java
@@ -635,7 +635,9 @@ public abstract class SegmentStages implements SegmentLock, LocksInterface {
                     " chucks, " + h.maxChunksPerEntry + " is maximum.");
         }
         long lowestPossiblyFreeChunk = lowestPossiblyFreeChunk();
-        if (lowestPossiblyFreeChunk == h.actualChunksPerSegmentTier)
+        if (lowestPossiblyFreeChunk + chunks > h.actualChunksPerSegmentTier)
+            return -1;
+        if (tierEntries() >= h.maxEntriesPerHashLookup)
             return -1;
         assert lowestPossiblyFreeChunk < h.actualChunksPerSegmentTier;
         long ret = freeList.setNextNContinuousClearBits(lowestPossiblyFreeChunk, chunks);