diff --git a/compiler/rustc_attr/src/builtin.rs b/compiler/rustc_attr/src/builtin.rs
index 26baaf07880..5dd4236a8dd 100644
--- a/compiler/rustc_attr/src/builtin.rs
+++ b/compiler/rustc_attr/src/builtin.rs
@@ -586,12 +586,14 @@ pub fn eval_condition(
                     return false;
                 }
             };
-            let channel = env!("CFG_RELEASE_CHANNEL");
-            let nightly = channel == "nightly" || channel == "dev";
             let rustc_version = parse_version(env!("CFG_RELEASE"), true).unwrap();
 
-            // See https://github.com/rust-lang/rust/issues/64796#issuecomment-625474439 for details
-            if nightly { rustc_version > min_version } else { rustc_version >= min_version }
+            // See https://github.com/rust-lang/rust/issues/64796#issuecomment-640851454 for details
+            if sess.assume_incomplete_release {
+                rustc_version > min_version
+            } else {
+                rustc_version >= min_version
+            }
         }
         ast::MetaItemKind::List(ref mis) => {
             for mi in mis.iter() {
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index 55d521a9b5f..762a8da632e 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -538,6 +538,7 @@ fn test_debugging_options_tracking_hash() {
     // This list is in alphabetical order.
     tracked!(allow_features, Some(vec![String::from("lang_items")]));
     tracked!(always_encode_mir, true);
+    tracked!(assume_incomplete_release, true);
     tracked!(asm_comments, true);
     tracked!(binary_dep_depinfo, true);
     tracked!(chalk, true);
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 30af65e49a0..e8e6a17b4d8 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -856,6 +856,8 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
         "only allow the listed language features to be enabled in code (space separated)"),
     always_encode_mir: bool = (false, parse_bool, [TRACKED],
         "encode MIR of all functions into the crate metadata (default: no)"),
+    assume_incomplete_release: bool = (false, parse_bool, [TRACKED],
+        "make cfg(version) treat the current version as incomplete (default: no)"),
     asm_comments: bool = (false, parse_bool, [TRACKED],
         "generate comments into the assembly (may change behavior) (default: no)"),
     ast_json: bool = (false, parse_bool, [UNTRACKED],
diff --git a/compiler/rustc_session/src/parse.rs b/compiler/rustc_session/src/parse.rs
index b1a48342417..81b38347414 100644
--- a/compiler/rustc_session/src/parse.rs
+++ b/compiler/rustc_session/src/parse.rs
@@ -138,6 +138,8 @@ pub struct ParseSess {
     pub env_depinfo: Lock<FxHashSet<(Symbol, Option<Symbol>)>>,
     /// All the type ascriptions expressions that have had a suggestion for likely path typo.
     pub type_ascription_path_suggestions: Lock<FxHashSet<Span>>,
+    /// Whether cfg(version) should treat the current release as incomplete
+    pub assume_incomplete_release: bool,
 }
 
 impl ParseSess {
@@ -164,6 +166,7 @@ impl ParseSess {
             reached_eof: Lock::new(false),
             env_depinfo: Default::default(),
             type_ascription_path_suggestions: Default::default(),
+            assume_incomplete_release: false,
         }
     }
 
diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs
index 6d018542286..891b9616c2c 100644
--- a/compiler/rustc_session/src/session.rs
+++ b/compiler/rustc_session/src/session.rs
@@ -1336,7 +1336,8 @@ pub fn build_session(
         None
     };
 
-    let parse_sess = ParseSess::with_span_handler(span_diagnostic, source_map);
+    let mut parse_sess = ParseSess::with_span_handler(span_diagnostic, source_map);
+    parse_sess.assume_incomplete_release = sopts.debugging_opts.assume_incomplete_release;
     let sysroot = match &sopts.maybe_sysroot {
         Some(sysroot) => sysroot.clone(),
         None => filesearch::get_or_default_sysroot(),