diff --git a/freqtrade/resolvers/strategy_resolver.py b/freqtrade/resolvers/strategy_resolver.py
index 0265ad6c3..44d590b67 100644
--- a/freqtrade/resolvers/strategy_resolver.py
+++ b/freqtrade/resolvers/strategy_resolver.py
@@ -217,15 +217,19 @@ class StrategyResolver(IResolver):
                 raise OperationalException(
                     "`populate_exit_trend` or `populate_sell_trend` must be implemented.")
 
-            strategy._populate_fun_len = len(getfullargspec(strategy.populate_indicators).args)
-            strategy._buy_fun_len = len(getfullargspec(strategy.populate_buy_trend).args)
-            strategy._sell_fun_len = len(getfullargspec(strategy.populate_sell_trend).args)
+            _populate_fun_len = len(getfullargspec(strategy.populate_indicators).args)
+            _buy_fun_len = len(getfullargspec(strategy.populate_buy_trend).args)
+            _sell_fun_len = len(getfullargspec(strategy.populate_sell_trend).args)
             if any(x == 2 for x in [
-                strategy._populate_fun_len,
-                strategy._buy_fun_len,
-                strategy._sell_fun_len
+                _populate_fun_len,
+                _buy_fun_len,
+                _sell_fun_len
             ]):
-                strategy.INTERFACE_VERSION = 1
+                raise OperationalException(
+                    "Strategy Interface v1 is no longer supported. "
+                    "Please update your strategy to implement "
+                    "`populate_indicators`, `populate_entry_trend` and `populate_exit_trend` "
+                    "with the metadata argument. ")
         return strategy
 
     @staticmethod
diff --git a/freqtrade/strategy/interface.py b/freqtrade/strategy/interface.py
index afcc1aa99..0ec3895bc 100644
--- a/freqtrade/strategy/interface.py
+++ b/freqtrade/strategy/interface.py
@@ -3,7 +3,6 @@ IStrategy interface
 This module defines the interface to apply for strategies
 """
 import logging
-import warnings
 from abc import ABC, abstractmethod
 from datetime import datetime, timedelta, timezone
 from typing import Dict, List, Optional, Tuple, Union
@@ -44,14 +43,11 @@ class IStrategy(ABC, HyperStrategyMixin):
     """
     # Strategy interface version
     # Default to version 2
-    # Version 1 is the initial interface without metadata dict
+    # Version 1 is the initial interface without metadata dict - deprecated and no longer supported.
     # Version 2 populate_* include metadata dict
     # Version 3 - First version with short and leverage support
     INTERFACE_VERSION: int = 3
 
-    _populate_fun_len: int = 0
-    _buy_fun_len: int = 0
-    _sell_fun_len: int = 0
     _ft_params_from_file: Dict
     # associated minimal roi
     minimal_roi: Dict = {}
@@ -1090,12 +1086,7 @@ class IStrategy(ABC, HyperStrategyMixin):
             dataframe = _create_and_merge_informative_pair(
                 self, dataframe, metadata, inf_data, populate_fn)
 
-        if self._populate_fun_len == 2:
-            warnings.warn("deprecated - check out the Sample strategy to see "
-                          "the current function headers!", DeprecationWarning)
-            return self.populate_indicators(dataframe)  # type: ignore
-        else:
-            return self.populate_indicators(dataframe, metadata)
+        return self.populate_indicators(dataframe, metadata)
 
     def advise_entry(self, dataframe: DataFrame, metadata: dict) -> DataFrame:
         """
@@ -1109,12 +1100,7 @@ class IStrategy(ABC, HyperStrategyMixin):
 
         logger.debug(f"Populating enter signals for pair {metadata.get('pair')}.")
 
-        if self._buy_fun_len == 2:
-            warnings.warn("deprecated - check out the Sample strategy to see "
-                          "the current function headers!", DeprecationWarning)
-            df = self.populate_buy_trend(dataframe)  # type: ignore
-        else:
-            df = self.populate_entry_trend(dataframe, metadata)
+        df = self.populate_entry_trend(dataframe, metadata)
         if 'enter_long' not in df.columns:
             df = df.rename({'buy': 'enter_long', 'buy_tag': 'enter_tag'}, axis='columns')
 
@@ -1129,14 +1115,8 @@ class IStrategy(ABC, HyperStrategyMixin):
             currently traded pair
         :return: DataFrame with exit column
         """
-
         logger.debug(f"Populating exit signals for pair {metadata.get('pair')}.")
-        if self._sell_fun_len == 2:
-            warnings.warn("deprecated - check out the Sample strategy to see "
-                          "the current function headers!", DeprecationWarning)
-            df = self.populate_sell_trend(dataframe)  # type: ignore
-        else:
-            df = self.populate_exit_trend(dataframe, metadata)
+        df = self.populate_exit_trend(dataframe, metadata)
         if 'exit_long' not in df.columns:
             df = df.rename({'sell': 'exit_long'}, axis='columns')
         return df