diff --git a/build.rs b/build.rs
index a06f009c..89e2ab39 100644
--- a/build.rs
+++ b/build.rs
@@ -14,6 +14,10 @@
 //     procmacro2_semver_exempt surface area is implemented by using the
 //     nightly-only proc_macro API.
 //
+//  "hygiene"
+//    Enable Span::mixed_site() and non-dummy behavior of Span::resolved_at
+//    and Span::located_at. Enabled on Rust 1.45+.
+//
 // "proc_macro_span"
 //     Enable non-dummy behavior of Span::start and Span::end methods which
 //     requires an unstable compiler feature. Enabled when building with
diff --git a/src/fallback.rs b/src/fallback.rs
index 554c87ea..eac975f2 100644
--- a/src/fallback.rs
+++ b/src/fallback.rs
@@ -384,17 +384,12 @@ impl Span {
         Span::call_site()
     }
 
-    #[cfg(procmacro2_semver_exempt)]
-    pub fn resolved_at(&self, _other: Span) -> Span {
-        // Stable spans consist only of line/column information, so
-        // `resolved_at` and `located_at` only select which span the
-        // caller wants line/column information from.
-        *self
+    pub fn resolved_at(&self, other: Span) -> Span {
+        other
     }
 
-    #[cfg(procmacro2_semver_exempt)]
-    pub fn located_at(&self, other: Span) -> Span {
-        other
+    pub fn located_at(&self, _other: Span) -> Span {
+        *self
     }
 
     #[cfg(procmacro2_semver_exempt)]
diff --git a/src/lib.rs b/src/lib.rs
index 725e1214..98ba5950 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -369,8 +369,8 @@ impl Span {
     /// Creates a new span with the same line/column information as `self` but
     /// that resolves symbols as though it were at `other`.
     ///
-    /// This method is semver exempt and not exposed by default.
-    #[cfg(procmacro2_semver_exempt)]
+    /// On versions of Rust prior to 1.45, this returns `other` to preserve the
+    /// name resolution behavior while discarding location information.
     pub fn resolved_at(&self, other: Span) -> Span {
         Span::_new(self.inner.resolved_at(other.inner))
     }
@@ -378,8 +378,8 @@ impl Span {
     /// Creates a new span with the same name resolution behavior as `self` but
     /// with the line/column information of `other`.
     ///
-    /// This method is semver exempt and not exposed by default.
-    #[cfg(procmacro2_semver_exempt)]
+    /// On versions of Rust prior to 1.45, this returns `self` to preserve the
+    /// name resolution behavior while discarding location information.
     pub fn located_at(&self, other: Span) -> Span {
         Span::_new(self.inner.located_at(other.inner))
     }
diff --git a/src/wrapper.rs b/src/wrapper.rs
index f9429b7b..32c71fad 100644
--- a/src/wrapper.rs
+++ b/src/wrapper.rs
@@ -394,19 +394,29 @@ impl Span {
         }
     }
 
-    #[cfg(super_unstable)]
     pub fn resolved_at(&self, other: Span) -> Span {
         match (self, other) {
+            #[cfg(hygiene)]
             (Span::Compiler(a), Span::Compiler(b)) => Span::Compiler(a.resolved_at(b)),
+
+            // Name resolution affects semantics, but location is only cosmetic
+            #[cfg(not(hygiene))]
+            (Span::Compiler(_), Span::Compiler(_)) => other,
+
             (Span::Fallback(a), Span::Fallback(b)) => Span::Fallback(a.resolved_at(b)),
             _ => mismatch(),
         }
     }
 
-    #[cfg(super_unstable)]
     pub fn located_at(&self, other: Span) -> Span {
         match (self, other) {
+            #[cfg(hygiene)]
             (Span::Compiler(a), Span::Compiler(b)) => Span::Compiler(a.located_at(b)),
+
+            // Name resolution affects semantics, but location is only cosmetic
+            #[cfg(not(hygiene))]
+            (Span::Compiler(_), Span::Compiler(_)) => *self,
+
             (Span::Fallback(a), Span::Fallback(b)) => Span::Fallback(a.located_at(b)),
             _ => mismatch(),
         }