diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index f7af51e47526c..45e598531b969 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -348,12 +348,6 @@ declare_lint! {
 
 /// Some lints that are buffered from `libsyntax`. See `syntax::early_buffered_lints`.
 pub mod parser {
-    declare_lint! {
-        pub QUESTION_MARK_MACRO_SEP,
-        Allow,
-        "detects the use of `?` as a macro separator"
-    }
-
     declare_lint! {
         pub ILL_FORMED_ATTRIBUTE_INPUT,
         Warn,
@@ -444,7 +438,6 @@ declare_lint_pass! {
         PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
         MACRO_USE_EXTERN_CRATE,
         MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS,
-        parser::QUESTION_MARK_MACRO_SEP,
         parser::ILL_FORMED_ATTRIBUTE_INPUT,
         DEPRECATED_IN_FUTURE,
         AMBIGUOUS_ASSOCIATED_ITEMS,
diff --git a/src/librustc/lint/mod.rs b/src/librustc/lint/mod.rs
index 041944d887bd9..309af4b72c127 100644
--- a/src/librustc/lint/mod.rs
+++ b/src/librustc/lint/mod.rs
@@ -27,7 +27,7 @@ use crate::hir::def_id::{CrateNum, LOCAL_CRATE};
 use crate::hir::intravisit;
 use crate::hir;
 use crate::lint::builtin::BuiltinLintDiagnostics;
-use crate::lint::builtin::parser::{QUESTION_MARK_MACRO_SEP, ILL_FORMED_ATTRIBUTE_INPUT};
+use crate::lint::builtin::parser::ILL_FORMED_ATTRIBUTE_INPUT;
 use crate::session::{Session, DiagnosticMessageId};
 use crate::ty::TyCtxt;
 use crate::ty::query::Providers;
@@ -80,7 +80,6 @@ impl Lint {
     /// Returns the `rust::lint::Lint` for a `syntax::early_buffered_lints::BufferedEarlyLintId`.
     pub fn from_parser_lint_id(lint_id: BufferedEarlyLintId) -> &'static Self {
         match lint_id {
-            BufferedEarlyLintId::QuestionMarkMacroSep => QUESTION_MARK_MACRO_SEP,
             BufferedEarlyLintId::IllFormedAttributeInput => ILL_FORMED_ATTRIBUTE_INPUT,
         }
     }
diff --git a/src/librustc_lint/lib.rs b/src/librustc_lint/lib.rs
index ec8a9c6fbb2a8..d808a15982e37 100644
--- a/src/librustc_lint/lib.rs
+++ b/src/librustc_lint/lib.rs
@@ -42,7 +42,6 @@ use rustc::lint::builtin::{
     INTRA_DOC_LINK_RESOLUTION_FAILURE,
     MISSING_DOC_CODE_EXAMPLES,
     PRIVATE_DOC_TESTS,
-    parser::QUESTION_MARK_MACRO_SEP,
     parser::ILL_FORMED_ATTRIBUTE_INPUT,
 };
 use rustc::session;
@@ -404,11 +403,6 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
             reference: "issue #50504 <https://github.com/rust-lang/rust/issues/50504>",
             edition: None,
         },
-        FutureIncompatibleInfo {
-            id: LintId::of(QUESTION_MARK_MACRO_SEP),
-            reference: "issue #48075 <https://github.com/rust-lang/rust/issues/48075>",
-            edition: Some(Edition::Edition2018),
-        },
         FutureIncompatibleInfo {
             id: LintId::of(MACRO_EXPANDED_MACRO_EXPORTS_ACCESSED_BY_ABSOLUTE_PATHS),
             reference: "issue #52234 <https://github.com/rust-lang/rust/issues/52234>",
diff --git a/src/libsyntax/early_buffered_lints.rs b/src/libsyntax/early_buffered_lints.rs
index 598c8459d1590..b26a1165fed1d 100644
--- a/src/libsyntax/early_buffered_lints.rs
+++ b/src/libsyntax/early_buffered_lints.rs
@@ -9,8 +9,6 @@ use syntax_pos::MultiSpan;
 /// Since we cannot import `LintId`s from `rustc::lint`, we define some Ids here which can later be
 /// passed to `rustc::lint::Lint::from_parser_lint_id` to get a `rustc::lint::Lint`.
 pub enum BufferedEarlyLintId {
-    /// Usage of `?` as a macro separator is deprecated.
-    QuestionMarkMacroSep,
     IllFormedAttributeInput,
 }