diff --git a/tests/test_ulid.py b/tests/test_ulid.py
index 11ae933..f9e0e8e 100644
--- a/tests/test_ulid.py
+++ b/tests/test_ulid.py
@@ -74,6 +74,14 @@ def test_same_millisecond_overflow() -> None:
         ULID()
 
 
+def test_same_millisecond_monotonic_sorting_without_frozen_time() -> None:
+    previous_ulid = "" 
+    for i in range(10000):
+        new_ulid = ULID()
+        assert new_ulid > previous_ulid
+        previous_ulid = new_ulid
+
+
 def assert_sorted(seq: list) -> None:
     last = seq[0]
     for item in seq[1:]:
diff --git a/ulid/__init__.py b/ulid/__init__.py
index d327385..c22b342 100644
--- a/ulid/__init__.py
+++ b/ulid/__init__.py
@@ -69,10 +69,9 @@ def timestamp(self, value: float | None = None) -> int:
             raise ValueError("Value exceeds maximum possible timestamp")
         return value
 
-    def randomness(self) -> bytes:
+    def randomness(self, timestamp: int) -> bytes:
         with self.lock:
-            current_timestamp = self.timestamp()
-            if current_timestamp == self.prev_timestamp:
+            if timestamp == self.prev_timestamp:
                 if self.prev_randomness == constants.MAX_RANDOMNESS:
                     raise ValueError("Randomness within same millisecond exhausted")
                 randomness = self.increment_bytes(self.prev_randomness)
@@ -80,7 +79,7 @@ def randomness(self) -> bytes:
                 randomness = os.urandom(constants.RANDOMNESS_LEN)
 
             self.prev_randomness = randomness
-            self.prev_timestamp = current_timestamp
+            self.prev_timestamp = timestamp
         return randomness
 
     def increment_bytes(self, value: bytes) -> bytes:
@@ -148,8 +147,9 @@ def from_timestamp(cls, value: float) -> Self:
             >>> ULID.from_timestamp(time.time())
             ULID(01E75QWN5HKQ0JAVX9FG1K4YP4)
         """
-        timestamp = int.to_bytes(cls.provider.timestamp(value), constants.TIMESTAMP_LEN, "big")
-        randomness = cls.provider.randomness()
+        timestamp_value = cls.provider.timestamp(value)
+        timestamp = int.to_bytes(timestamp_value, constants.TIMESTAMP_LEN, "big")
+        randomness = cls.provider.randomness(timestamp_value)
         return cls.from_bytes(timestamp + randomness)
 
     @classmethod