diff --git a/compiler/rustc_builtin_macros/src/source_util.rs b/compiler/rustc_builtin_macros/src/source_util.rs
index bbc8e62d68f..be628c9202c 100644
--- a/compiler/rustc_builtin_macros/src/source_util.rs
+++ b/compiler/rustc_builtin_macros/src/source_util.rs
@@ -3,15 +3,17 @@
 use rustc_ast::token;
 use rustc_ast::tokenstream::TokenStream;
 use rustc_ast_pretty::pprust;
+use rustc_errors::PResult;
 use rustc_expand::base::{self, *};
 use rustc_expand::module::DirOwnership;
 use rustc_parse::parser::{ForceCollect, Parser};
 use rustc_parse::{self, new_parser_from_file};
 use rustc_session::lint::builtin::INCOMPLETE_INCLUDE;
 use rustc_span::symbol::Symbol;
-use rustc_span::{self, Pos, Span};
+use rustc_span::{self, FileName, Pos, Span};
 
 use smallvec::SmallVec;
+use std::path::PathBuf;
 use std::rc::Rc;
 
 // These macros all relate to the file system; they either return
@@ -102,7 +104,7 @@ pub fn expand_include<'cx>(
         return DummyResult::any(sp);
     };
     // The file will be added to the code map by the parser
-    let file = match cx.resolve_path(file, sp) {
+    let file = match resolve_path(cx, file, sp) {
         Ok(f) => f,
         Err(mut err) => {
             err.emit();
@@ -171,7 +173,7 @@ pub fn expand_include_str(
     let Some(file) = get_single_str_from_tts(cx, sp, tts, "include_str!") else {
         return DummyResult::any(sp);
     };
-    let file = match cx.resolve_path(file, sp) {
+    let file = match resolve_path(cx, file, sp) {
         Ok(f) => f,
         Err(mut err) => {
             err.emit();
@@ -205,7 +207,7 @@ pub fn expand_include_bytes(
     let Some(file) = get_single_str_from_tts(cx, sp, tts, "include_bytes!") else {
         return DummyResult::any(sp);
     };
-    let file = match cx.resolve_path(file, sp) {
+    let file = match resolve_path(cx, file, sp) {
         Ok(f) => f,
         Err(mut err) => {
             err.emit();
@@ -220,3 +222,40 @@ pub fn expand_include_bytes(
         }
     }
 }
+
+/// Resolves a `path` mentioned inside Rust code, returning an absolute path.
+///
+/// This unifies the logic used for resolving `include_X!`.
+fn resolve_path<'a>(
+    cx: &mut ExtCtxt<'a>,
+    path: impl Into<PathBuf>,
+    span: Span,
+) -> PResult<'a, PathBuf> {
+    let path = path.into();
+
+    // Relative paths are resolved relative to the file in which they are found
+    // after macro expansion (that is, they are unhygienic).
+    if !path.is_absolute() {
+        let callsite = span.source_callsite();
+        let mut result = match cx.source_map().span_to_filename(callsite) {
+            FileName::Real(name) => name
+                .into_local_path()
+                .expect("attempting to resolve a file path in an external file"),
+            FileName::DocTest(path, _) => path,
+            other => {
+                return Err(cx.struct_span_err(
+                    span,
+                    &format!(
+                        "cannot resolve relative path in non-file source `{}`",
+                        cx.source_map().filename_for_diagnostics(&other)
+                    ),
+                ));
+            }
+        };
+        result.pop();
+        result.push(path);
+        Ok(result)
+    } else {
+        Ok(path)
+    }
+}
diff --git a/compiler/rustc_expand/src/base.rs b/compiler/rustc_expand/src/base.rs
index d6b308cdf85..7f569af4abd 100644
--- a/compiler/rustc_expand/src/base.rs
+++ b/compiler/rustc_expand/src/base.rs
@@ -10,7 +10,7 @@
 use rustc_attr::{self as attr, Deprecation, Stability};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::sync::{self, Lrc};
-use rustc_errors::{Applicability, DiagnosticBuilder, ErrorGuaranteed, PResult};
+use rustc_errors::{Applicability, DiagnosticBuilder, ErrorGuaranteed};
 use rustc_lint_defs::builtin::PROC_MACRO_BACK_COMPAT;
 use rustc_lint_defs::BuiltinLintDiagnostics;
 use rustc_parse::{self, nt_to_tokenstream, parser, MACRO_ARGUMENTS};
@@ -20,7 +20,7 @@
 use rustc_span::hygiene::{AstPass, ExpnData, ExpnKind, LocalExpnId};
 use rustc_span::source_map::SourceMap;
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
-use rustc_span::{FileName, MultiSpan, Span, DUMMY_SP};
+use rustc_span::{MultiSpan, Span, DUMMY_SP};
 use smallvec::{smallvec, SmallVec};
 
 use std::default::Default;
@@ -1128,41 +1128,6 @@ pub fn def_site_path(&self, components: &[Symbol]) -> Vec<Ident> {
     pub fn check_unused_macros(&mut self) {
         self.resolver.check_unused_macros();
     }
-
-    /// Resolves a `path` mentioned inside Rust code, returning an absolute path.
-    ///
-    /// This unifies the logic used for resolving `include_X!`.
-    ///
-    /// FIXME: move this to `rustc_builtin_macros` and make it private.
-    pub fn resolve_path(&self, path: impl Into<PathBuf>, span: Span) -> PResult<'a, PathBuf> {
-        let path = path.into();
-
-        // Relative paths are resolved relative to the file in which they are found
-        // after macro expansion (that is, they are unhygienic).
-        if !path.is_absolute() {
-            let callsite = span.source_callsite();
-            let mut result = match self.source_map().span_to_filename(callsite) {
-                FileName::Real(name) => name
-                    .into_local_path()
-                    .expect("attempting to resolve a file path in an external file"),
-                FileName::DocTest(path, _) => path,
-                other => {
-                    return Err(self.struct_span_err(
-                        span,
-                        &format!(
-                            "cannot resolve relative path in non-file source `{}`",
-                            self.source_map().filename_for_diagnostics(&other)
-                        ),
-                    ));
-                }
-            };
-            result.pop();
-            result.push(path);
-            Ok(result)
-        } else {
-            Ok(path)
-        }
-    }
 }
 
 /// Extracts a string literal from the macro expanded version of `expr`,