diff --git a/cranelift/isle/isle/src/error.rs b/cranelift/isle/isle/src/error.rs
index 89c0ae4341..39b6adcf87 100644
--- a/cranelift/isle/isle/src/error.rs
+++ b/cranelift/isle/isle/src/error.rs
@@ -2,6 +2,8 @@
 
 use std::sync::Arc;
 
+use crate::lexer::Pos;
+
 /// Either `Ok(T)` or `Err(isle::Error)`.
 pub type Result<T> = std::result::Result<T, Error>;
 
@@ -82,8 +84,30 @@ impl std::fmt::Display for Error {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             Error::IoError { context, .. } => write!(f, "{}", context),
+
+            // Include locations directly in the `Display` output when
+            // we're not wrapping errors with miette (which provides
+            // its own way of showing locations and context).
+            #[cfg(not(feature = "miette-errors"))]
+            Error::ParseError { src, span, msg, .. } => write!(
+                f,
+                "{}: parse error: {}",
+                span.from.pretty_print_with_filename(&*src.name),
+                msg
+            ),
+            #[cfg(not(feature = "miette-errors"))]
+            Error::TypeError { src, span, msg, .. } => write!(
+                f,
+                "{}: type error: {}",
+                span.from.pretty_print_with_filename(&*src.name),
+                msg
+            ),
+
+            #[cfg(feature = "miette-errors")]
             Error::ParseError { msg, .. } => write!(f, "parse error: {}", msg),
+            #[cfg(feature = "miette-errors")]
             Error::TypeError { msg, .. } => write!(f, "type error: {}", msg),
+
             Error::Errors(_) => write!(
                 f,
                 "found {} errors:\n\n{}",
@@ -143,17 +167,27 @@ impl Source {
 #[derive(Clone, Debug)]
 pub struct Span {
     /// The byte offset of the start of the span.
-    pub from: usize,
+    pub from: Pos,
     /// The byte offset of the end of the span.
-    pub to: usize,
+    pub to: Pos,
 }
 
 impl Span {
     /// Create a new span that covers one character at the given offset.
-    pub fn new_single(offset: usize) -> Span {
+    pub fn new_single(pos: Pos) -> Span {
         Span {
-            from: offset,
-            to: offset + 1,
+            from: pos,
+            // This is a slight hack (we don't actually look at the
+            // file to find line/col of next char); but the span
+            // aspect, vs. just the starting point, is only relevant
+            // for miette and when miette is enabled we use only the
+            // `offset` here to provide its SourceSpans.
+            to: Pos {
+                file: pos.file,
+                offset: pos.offset + 1,
+                line: pos.line,
+                col: pos.col + 1,
+            },
         }
     }
 }
diff --git a/cranelift/isle/isle/src/error_miette.rs b/cranelift/isle/isle/src/error_miette.rs
index 4050b065ad..555b4e4aca 100644
--- a/cranelift/isle/isle/src/error_miette.rs
+++ b/cranelift/isle/isle/src/error_miette.rs
@@ -8,7 +8,7 @@ use miette::{SourceCode, SourceSpan};
 
 impl From<Span> for SourceSpan {
     fn from(span: Span) -> Self {
-        SourceSpan::new(span.from.into(), span.to.into())
+        SourceSpan::new(span.from.offset.into(), span.to.offset.into())
     }
 }
 
diff --git a/cranelift/isle/isle/src/lexer.rs b/cranelift/isle/isle/src/lexer.rs
index 996356c568..9a8a07e880 100644
--- a/cranelift/isle/isle/src/lexer.rs
+++ b/cranelift/isle/isle/src/lexer.rs
@@ -45,12 +45,17 @@ pub struct Pos {
 impl Pos {
     /// Print this source position as `file.isle:12:34`.
     pub fn pretty_print(&self, filenames: &[Arc<str>]) -> String {
-        format!("{}:{}:{}", filenames[self.file], self.line, self.col)
+        self.pretty_print_with_filename(&filenames[self.file])
     }
     /// Print this source position as `file.isle line 12`.
     pub fn pretty_print_line(&self, filenames: &[Arc<str>]) -> String {
         format!("{} line {}", filenames[self.file], self.line)
     }
+    /// As above for `pretty_print`, but with the specific filename
+    /// already provided.
+    pub fn pretty_print_with_filename(&self, filename: &str) -> String {
+        format!("{}:{}:{}", filename, self.line, self.col)
+    }
 }
 
 /// A token of ISLE source.
@@ -167,7 +172,7 @@ impl<'a> Lexer<'a> {
                 self.filenames[pos.file].clone(),
                 self.file_texts[pos.file].clone(),
             ),
-            span: Span::new_single(self.pos().offset),
+            span: Span::new_single(self.pos()),
         }
     }
 
diff --git a/cranelift/isle/isle/src/parser.rs b/cranelift/isle/isle/src/parser.rs
index 1427cdb2c4..c6b518f00a 100644
--- a/cranelift/isle/isle/src/parser.rs
+++ b/cranelift/isle/isle/src/parser.rs
@@ -39,7 +39,7 @@ impl<'a> Parser<'a> {
                 self.lexer.filenames[pos.file].clone(),
                 self.lexer.file_texts[pos.file].clone(),
             ),
-            span: Span::new_single(pos.offset),
+            span: Span::new_single(pos),
         }
     }
 
diff --git a/cranelift/isle/isle/src/sema.rs b/cranelift/isle/isle/src/sema.rs
index 07c861e3b5..db075d25f3 100644
--- a/cranelift/isle/isle/src/sema.rs
+++ b/cranelift/isle/isle/src/sema.rs
@@ -727,7 +727,7 @@ impl TypeEnv {
                 self.filenames[pos.file].clone(),
                 self.file_texts[pos.file].clone(),
             ),
-            span: Span::new_single(pos.offset),
+            span: Span::new_single(pos),
         };
         log!("{}", e);
         e