diff --git a/news/13634.bugfix.rst b/news/13634.bugfix.rst
new file mode 100644
index 00000000000..8df20c49d05
--- /dev/null
+++ b/news/13634.bugfix.rst
@@ -0,0 +1 @@
+Patch scheme to posix_prefix if posix_local and --prefix is specified
diff --git a/src/pip/_internal/locations/_sysconfig.py b/src/pip/_internal/locations/_sysconfig.py
index d4a448ece52..f44058bda89 100644
--- a/src/pip/_internal/locations/_sysconfig.py
+++ b/src/pip/_internal/locations/_sysconfig.py
@@ -155,6 +155,12 @@ def get_scheme(
     else:
         scheme_name = _infer_prefix()
 
+    # Special case: When installing into a custom prefix, use posix_prefix
+    # instead of posix_local because it should be used only to redirecting
+    # to /usr/local.
+    if prefix is not None and scheme_name == "posix_local":
+        scheme_name = "posix_prefix"
+
     # Special case: When installing into a custom prefix, use posix_prefix
     # instead of osx_framework_library. See _should_use_osx_framework_prefix()
     # docstring for details.