diff --git a/src/etcetra/client.py b/src/etcetra/client.py
index e63bc40..c975790 100644
--- a/src/etcetra/client.py
+++ b/src/etcetra/client.py
@@ -362,10 +362,7 @@ def get_prefix(
         encoding='utf-8',
     ):
         encoded_key = key.encode(encoding)
-        if key[-1] == '/' and len(key) >= 2:
-            range_end = encoded_key[:-2] + bytes([encoded_key[-2] + 1]) + b'/'
-        else:
-            range_end = encoded_key[:-1] + bytes([encoded_key[-1] + 1])
+        range_end = increment_last_byte(encoded_key)
         return rpc_pb2.RangeRequest(
             key=encoded_key,
             range_end=range_end,
@@ -408,10 +405,7 @@ def delete_prefix(
     ):
         # TODO: Implement prev_kv response
         encoded_key = key.encode(encoding)
-        if key[-1] == '/' and len(key) >= 2:
-            range_end = encoded_key[:-2] + bytes([encoded_key[-2] + 1]) + b'/'
-        else:
-            range_end = encoded_key[:-1] + bytes([encoded_key[-1] + 1])
+        range_end = increment_last_byte(encoded_key)
         return rpc_pb2.DeleteRangeRequest(
             key=encoded_key,
             range_end=range_end,
@@ -461,10 +455,7 @@ def keys_prefix(
         encoding='utf-8',
     ):
         encoded_key = key.encode(encoding)
-        if key[-1] == '/' and len(key) >= 2:
-            range_end = encoded_key[:-2] + bytes([encoded_key[-2] + 1]) + b'/'
-        else:
-            range_end = encoded_key[:-1] + bytes([encoded_key[-1] + 1])
+        range_end = increment_last_byte(encoded_key)
         return rpc_pb2.RangeRequest(
             key=encoded_key,
             range_end=range_end,
@@ -1309,10 +1300,7 @@ def watch_prefix(
             encoding = self.encoding
 
         encoded_key = key.encode(encoding)
-        if key[-1] == '/' and len(key) >= 2:
-            range_end = encoded_key[:-2] + bytes([encoded_key[-2] + 1]) + b'/'
-        else:
-            range_end = encoded_key[:-1] + bytes([encoded_key[-1] + 1])
+        range_end = increment_last_byte(encoded_key)
         return self._watch_impl(
             key.encode(encoding), encoding,
             ready_event=ready_event, filters=filters, prev_kv=prev_kv,
@@ -1671,3 +1659,13 @@ async def __aexit__(self, exc_type, exc, tb) -> Optional[bool]:
         self._lock_id = None
         self._lease_id = None
         return False
+
+
+def increment_last_byte(encoded_key):
+    s = bytearray(encoded_key)
+    for i in range(len(s) - 1, -1, -1):
+        if s[i] < 0xff:
+            s[i] += 1
+            return bytes(s[:i + 1])
+    else:
+        return b'\x00'