diff --git a/src/extra.rs b/src/extra.rs
index daf4ba1f..cbce1626 100644
--- a/src/extra.rs
+++ b/src/extra.rs
@@ -58,7 +58,7 @@ impl DelimSpan {
         match &self.inner {
             #[cfg(wrap_proc_macro)]
             DelimSpanEnum::Compiler { join, .. } => Span::_new(imp::Span::Compiler(*join)),
-            DelimSpanEnum::Fallback(span) => Span::_new_stable(*span),
+            DelimSpanEnum::Fallback(span) => Span::_new_fallback(*span),
         }
     }
 
@@ -73,7 +73,7 @@ impl DelimSpan {
                     join: open,
                 ..
             } => Span::_new(imp::Span::Compiler(*open)),
-            DelimSpanEnum::Fallback(span) => Span::_new_stable(span.first_byte()),
+            DelimSpanEnum::Fallback(span) => Span::_new_fallback(span.first_byte()),
         }
     }
 
@@ -88,7 +88,7 @@ impl DelimSpan {
                     join: close,
                 ..
             } => Span::_new(imp::Span::Compiler(*close)),
-            DelimSpanEnum::Fallback(span) => Span::_new_stable(span.last_byte()),
+            DelimSpanEnum::Fallback(span) => Span::_new_fallback(span.last_byte()),
         }
     }
 }
diff --git a/src/fallback.rs b/src/fallback.rs
index 52bdcf7b..fc3cd515 100644
--- a/src/fallback.rs
+++ b/src/fallback.rs
@@ -94,7 +94,7 @@ fn push_token_from_proc_macro(mut vec: RcVecMut<TokenTree>, token: TokenTree) {
             if literal.repr.starts_with('-') {
                 push_negative_literal(vec, literal);
             } else {
-                vec.push(TokenTree::Literal(crate::Literal::_new_stable(literal)));
+                vec.push(TokenTree::Literal(crate::Literal::_new_fallback(literal)));
             }
         }
         _ => vec.push(token),
@@ -104,9 +104,9 @@ fn push_token_from_proc_macro(mut vec: RcVecMut<TokenTree>, token: TokenTree) {
     fn push_negative_literal(mut vec: RcVecMut<TokenTree>, mut literal: Literal) {
         literal.repr.remove(0);
         let mut punct = crate::Punct::new('-', Spacing::Alone);
-        punct.set_span(crate::Span::_new_stable(literal.span));
+        punct.set_span(crate::Span::_new_fallback(literal.span));
         vec.push(TokenTree::Punct(punct));
-        vec.push(TokenTree::Literal(crate::Literal::_new_stable(literal)));
+        vec.push(TokenTree::Literal(crate::Literal::_new_fallback(literal)));
     }
 }
 
diff --git a/src/lib.rs b/src/lib.rs
index 9e0f7fde..9b53cf99 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -187,7 +187,7 @@ impl TokenStream {
         }
     }
 
-    fn _new_stable(inner: fallback::TokenStream) -> Self {
+    fn _new_fallback(inner: fallback::TokenStream) -> Self {
         TokenStream {
             inner: inner.into(),
             _marker: Marker,
@@ -381,7 +381,7 @@ impl Span {
         }
     }
 
-    fn _new_stable(inner: fallback::Span) -> Self {
+    fn _new_fallback(inner: fallback::Span) -> Self {
         Span {
             inner: inner.into(),
             _marker: Marker,
@@ -668,7 +668,7 @@ impl Group {
         Group { inner }
     }
 
-    fn _new_stable(inner: fallback::Group) -> Self {
+    fn _new_fallback(inner: fallback::Group) -> Self {
         Group {
             inner: inner.into(),
         }
@@ -1093,7 +1093,7 @@ impl Literal {
         }
     }
 
-    fn _new_stable(inner: fallback::Literal) -> Self {
+    fn _new_fallback(inner: fallback::Literal) -> Self {
         Literal {
             inner: inner.into(),
             _marker: Marker,
diff --git a/src/parse.rs b/src/parse.rs
index 2a87948a..82291da1 100644
--- a/src/parse.rs
+++ b/src/parse.rs
@@ -217,13 +217,13 @@ pub(crate) fn token_stream(mut input: Cursor) -> Result<TokenStream, LexError> {
                 hi: input.off,
             });
             trees = outer;
-            trees.push_token_from_parser(TokenTree::Group(crate::Group::_new_stable(g)));
+            trees.push_token_from_parser(TokenTree::Group(crate::Group::_new_fallback(g)));
         } else {
             let (rest, mut tt) = match leaf_token(input) {
                 Ok((rest, tt)) => (rest, tt),
                 Err(Reject) => return Err(lex_error(input)),
             };
-            tt.set_span(crate::Span::_new_stable(Span {
+            tt.set_span(crate::Span::_new_fallback(Span {
                 #[cfg(span_locations)]
                 lo,
                 #[cfg(span_locations)]
@@ -251,7 +251,7 @@ fn lex_error(cursor: Cursor) -> LexError {
 fn leaf_token(input: Cursor) -> PResult<TokenTree> {
     if let Ok((input, l)) = literal(input) {
         // must be parsed before ident
-        Ok((input, TokenTree::Literal(crate::Literal::_new_stable(l))))
+        Ok((input, TokenTree::Literal(crate::Literal::_new_fallback(l))))
     } else if let Ok((input, p)) = punct(input) {
         Ok((input, TokenTree::Punct(p)))
     } else if let Ok((input, i)) = ident(input) {
@@ -795,7 +795,7 @@ fn doc_comment<'a>(input: Cursor<'a>, trees: &mut TokenStreamBuilder) -> PResult
     #[cfg(span_locations)]
     let lo = input.off;
     let (rest, (comment, inner)) = doc_comment_contents(input)?;
-    let span = crate::Span::_new_stable(Span {
+    let span = crate::Span::_new_fallback(Span {
         #[cfg(span_locations)]
         lo,
         #[cfg(span_locations)]
@@ -831,7 +831,7 @@ fn doc_comment<'a>(input: Cursor<'a>, trees: &mut TokenStreamBuilder) -> PResult
     bracketed.push_token_from_parser(TokenTree::Punct(equal));
     bracketed.push_token_from_parser(TokenTree::Literal(literal));
     let group = Group::new(Delimiter::Bracket, bracketed.build());
-    let mut group = crate::Group::_new_stable(group);
+    let mut group = crate::Group::_new_fallback(group);
     group.set_span(span);
     trees.push_token_from_parser(TokenTree::Group(group));
 
diff --git a/src/wrapper.rs b/src/wrapper.rs
index f5ec06b6..720dcdd3 100644
--- a/src/wrapper.rs
+++ b/src/wrapper.rs
@@ -40,7 +40,7 @@ impl LexError {
 }
 
 fn mismatch() -> ! {
-    panic!("stable/nightly mismatch")
+    panic!("compiler/fallback mismatch")
 }
 
 impl DeferredTokenStream {