diff --git a/ConflictSet.cpp b/ConflictSet.cpp
index 549d68e..bf59121 100644
--- a/ConflictSet.cpp
+++ b/ConflictSet.cpp
@@ -1220,11 +1220,13 @@ getChildUpdatingMaxVersion(Node3 *self, std::span<const uint8_t> &remaining,
     return nullptr;
   }
   Node *c = self->children[i];
-  int commonLen = std::min<int>(c->partialKeyLen, key.size());
-  int partialKeyIndex =
-      longestCommonPrefix(c->partialKey(), key.data(), commonLen);
-  if (partialKeyIndex < c->partialKeyLen) {
-    return nullptr;
+  if (c->partialKeyLen > 0) {
+    int commonLen = std::min<int>(c->partialKeyLen, key.size());
+    int partialKeyIndex =
+        longestCommonPrefix(c->partialKey(), key.data(), commonLen);
+    if (partialKeyIndex < c->partialKeyLen) {
+      return nullptr;
+    }
   }
   remaining = key.subspan(c->partialKeyLen, key.size() - c->partialKeyLen);
   self->childMaxVersion[i] = maxVersion;
@@ -1241,11 +1243,13 @@ getChildUpdatingMaxVersion(Node16 *self, std::span<const uint8_t> &remaining,
     return nullptr;
   }
   Node *c = self->children[i];
-  int commonLen = std::min<int>(c->partialKeyLen, key.size());
-  int partialKeyIndex =
-      longestCommonPrefix(c->partialKey(), key.data(), commonLen);
-  if (partialKeyIndex < c->partialKeyLen) {
-    return nullptr;
+  if (c->partialKeyLen > 0) {
+    int commonLen = std::min<int>(c->partialKeyLen, key.size());
+    int partialKeyIndex =
+        longestCommonPrefix(c->partialKey(), key.data(), commonLen);
+    if (partialKeyIndex < c->partialKeyLen) {
+      return nullptr;
+    }
   }
   remaining = key.subspan(c->partialKeyLen, key.size() - c->partialKeyLen);
   self->childMaxVersion[i] = maxVersion;
@@ -1262,11 +1266,13 @@ getChildUpdatingMaxVersion(Node48 *self, std::span<const uint8_t> &remaining,
     return nullptr;
   }
   Node *c = self->children[i];
-  int commonLen = std::min<int>(c->partialKeyLen, key.size());
-  int partialKeyIndex =
-      longestCommonPrefix(c->partialKey(), key.data(), commonLen);
-  if (partialKeyIndex < c->partialKeyLen) {
-    return nullptr;
+  if (c->partialKeyLen > 0) {
+    int commonLen = std::min<int>(c->partialKeyLen, key.size());
+    int partialKeyIndex =
+        longestCommonPrefix(c->partialKey(), key.data(), commonLen);
+    if (partialKeyIndex < c->partialKeyLen) {
+      return nullptr;
+    }
   }
   remaining = key.subspan(c->partialKeyLen, key.size() - c->partialKeyLen);
   self->childMaxVersion[i] = maxVersion;
@@ -1285,11 +1291,13 @@ getChildUpdatingMaxVersion(Node256 *self, std::span<const uint8_t> &remaining,
     return nullptr;
   }
   Node *c = n;
-  int commonLen = std::min<int>(c->partialKeyLen, key.size());
-  int partialKeyIndex =
-      longestCommonPrefix(c->partialKey(), key.data(), commonLen);
-  if (partialKeyIndex < c->partialKeyLen) {
-    return nullptr;
+  if (c->partialKeyLen > 0) {
+    int commonLen = std::min<int>(c->partialKeyLen, key.size());
+    int partialKeyIndex =
+        longestCommonPrefix(c->partialKey(), key.data(), commonLen);
+    if (partialKeyIndex < c->partialKeyLen) {
+      return nullptr;
+    }
   }
   remaining = key.subspan(c->partialKeyLen, key.size() - c->partialKeyLen);
   self->childMaxVersion[index] = maxVersion;