diff --git a/cxxheaderparser/types.py b/cxxheaderparser/types.py
index 5cd2ffe..e078a4a 100644
--- a/cxxheaderparser/types.py
+++ b/cxxheaderparser/types.py
@@ -374,9 +374,9 @@ class PointerToMember:
         v = " volatile" if self.volatile else ""
         ptr_to = self.ptr_to
         if isinstance(ptr_to, (Array, FunctionType)):
-            return ptr_to.format_decl(f"({base_type.format()}::*{c}{v})")
+            return ptr_to.format_decl(f"({self.base_type.format()}::*{c}{v})")
         else:
-            return f"{ptr_to.format()} {base_type.format()}::*{c}{v}"
+            return f"{ptr_to.format()} {self.base_type.format()}::*{c}{v}"
 
     def format_decl(self, name: str):
         """Format as a named declaration"""
@@ -384,9 +384,9 @@ class PointerToMember:
         v = " volatile" if self.volatile else ""
         ptr_to = self.ptr_to
         if isinstance(ptr_to, (Array, FunctionType)):
-            return ptr_to.format_decl(f"({base_type.format()}::*{c}{v} {name})")
+            return ptr_to.format_decl(f"({self.base_type.format()}::*{c}{v} {name})")
         else:
-            return f"{ptr_to.format()} {base_type.format()}::*{c}{v} {name}"
+            return f"{ptr_to.format()} {self.base_type.format()}::*{c}{v} {name}"