diff --git a/ape_vyper/compiler.py b/ape_vyper/compiler.py
index 047e4c07..21ae1b37 100644
--- a/ape_vyper/compiler.py
+++ b/ape_vyper/compiler.py
@@ -141,7 +141,9 @@ def get_optimization_pragma(source: Union[str, Path]) -> Optional[str]:
     return pragma_match.groups()[0]
 
 
-def get_optimization_pragma_map(contract_filepaths: List[Path]) -> Dict[Optimization, Set[Path]]:
+def get_optimization_pragma_map(
+    contract_filepaths: Sequence[Path],
+) -> Dict[Optimization, Set[Path]]:
     optimization_pragma_map: Dict[Optimization, Set[Path]] = {}
     for path in contract_filepaths:
         pragma = get_optimization_pragma(path) or True
@@ -166,7 +168,7 @@ def evm_version(self) -> Optional[str]:
         return self.settings.evm_version
 
     def get_imports(
-        self, contract_filepaths: List[Path], base_path: Optional[Path] = None
+        self, contract_filepaths: Sequence[Path], base_path: Optional[Path] = None
     ) -> Dict[str, List[str]]:
         base_path = (base_path or self.project_manager.contracts_folder).absolute()
         import_map = {}
@@ -494,20 +496,8 @@ def compile_code(self, code: str, base_path: Optional[Path] = None, **kwargs) ->
             **kwargs,
         )
 
-    def get_optimization_pragma_map(
-        self, contract_filepaths: List[Path]
-    ) -> Dict[Optimization, Set[Path]]:
-        optimization_pragma_map: Dict[Optimization, Set[Path]] = {}
-        for path in contract_filepaths:
-            pragma = get_optimization_pragma(path) or True
-            if pragma not in optimization_pragma_map:
-                optimization_pragma_map[pragma] = set()
-            optimization_pragma_map[pragma].add(path)
-
-        return optimization_pragma_map
-
     def get_version_map(
-        self, contract_filepaths: List[Path], base_path: Optional[Path] = None
+        self, contract_filepaths: Sequence[Path], base_path: Optional[Path] = None
     ) -> Dict[Version, Set[Path]]:
         version_map: Dict[Version, Set[Path]] = {}
         source_path_by_version_spec: Dict[SpecifierSet, Set[Path]] = {}
@@ -569,7 +559,7 @@ def get_version_map(
         return version_map
 
     def get_compiler_settings(
-        self, contract_filepaths: List[Path], base_path: Optional[Path] = None
+        self, contract_filepaths: Sequence[Path], base_path: Optional[Path] = None
     ) -> Dict[Version, Dict]:
         valid_paths = [p for p in contract_filepaths if p.suffix == ".vy"]
         contracts_path = base_path or self.config_manager.contracts_folder