diff --git a/vasm_core/src/parse_error.rs b/vasm_core/src/parse_error.rs
index 7fce027..49f5b32 100644
--- a/vasm_core/src/parse_error.rs
+++ b/vasm_core/src/parse_error.rs
@@ -2,12 +2,42 @@ use std::fmt::{Display, Formatter};
 
 use vcore::opcodes::InvalidMnemonic;
 
+#[derive(Debug, PartialEq, Clone)]
+pub struct Location {
+    pub line_num: usize,
+    pub file: String,
+}
+
 #[derive(Debug, PartialEq, Clone)]
 pub enum ParseError {
     LineParseFailure,
     InvalidInstruction(String),
 }
 
+impl Display for Location {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}:{}", self.file, self.line_num)
+    }
+}
+
+impl Default for Location {
+    fn default() -> Self {
+        Location {
+            line_num: 0,
+            file: "<none>".to_string(),
+        }
+    }
+}
+
+impl From<usize> for Location {
+    fn from(line: usize) -> Self {
+        Self {
+            line_num: line,
+            file: "<none>".to_string(),
+        }
+    }
+}
+
 impl<'a> From<InvalidMnemonic<'a>> for ParseError {
     fn from(err: InvalidMnemonic<'a>) -> Self {
         Self::InvalidInstruction(err.0.into())
@@ -26,43 +56,43 @@ impl Display for ParseError {
 
 #[derive(Debug, Clone, PartialEq)]
 pub enum AssembleError {
-    ParseError(usize, ParseError),
-    EquResolveError(usize, String, EvalError),
-    EquDuplicateError(usize, String),
-    OrgResolveError(usize, EvalError),
-    ArgError(usize, EvalError),
+    ParseError(Location, ParseError),
+    EquResolveError(Location, String, EvalError),
+    EquDuplicateError(Location, String),
+    OrgResolveError(Location, EvalError),
+    ArgError(Location, EvalError),
     NoCode,
-    IncludeError(usize, String),
+    IncludeError(Location, String),
     FileError(String),
-    MacroError(usize),
+    MacroError(Location),
 }
 
 impl Display for AssembleError {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         match self {
             AssembleError::EquResolveError(line, name, err) => {
-                write!(f, "Cannot resolve .equ {} on line {}: {}", name, line, err)
+                write!(f, "Cannot resolve .equ {} at {}: {}", name, line, err)
             }
             AssembleError::EquDuplicateError(line, name) => {
-                write!(f, "Duplicate .equ {} on line {}", name, line)
+                write!(f, "Duplicate .equ {} at {}", name, line)
             }
             AssembleError::OrgResolveError(line, err) => {
-                write!(f, "Cannot resolve .org on line {}: {}", line, err)
+                write!(f, "Cannot resolve .org at {}: {}", line, err)
             }
             AssembleError::ArgError(line, err) => {
-                write!(f, "Cannot calculate argument on line {}: {}", line, err)
+                write!(f, "Cannot calculate argument at {}: {}", line, err)
             }
             AssembleError::NoCode => {
                 write!(f, "No output would be generated by this code")
             }
             AssembleError::ParseError(line, err) => {
-                write!(f, "Parse error on line {}: {}", line, err)
+                write!(f, "Parse error at {}: {}", line, err)
             }
             AssembleError::IncludeError(line, file) => {
-                write!(f, "Cannot read \"{}\" on line {}", file, line)
+                write!(f, "Cannot read \"{}\" at {}", file, line)
             }
             AssembleError::MacroError(line) => {
-                write!(f, "Malformed macro control structure on line {}", line)
+                write!(f, "Malformed macro control structure at {}", line)
             }
             AssembleError::FileError(file) => {
                 write!(f, "File read error in {}", file)
diff --git a/vasm_core/src/vasm_assembler.rs b/vasm_core/src/vasm_assembler.rs
index 115f0a2..86adcc2 100644
--- a/vasm_core/src/vasm_assembler.rs
+++ b/vasm_core/src/vasm_assembler.rs
@@ -1,5 +1,5 @@
 use crate::ast::{Label, Scope, VASMLine};
-use crate::parse_error::AssembleError;
+use crate::parse_error::{AssembleError, Location};
 use crate::vasm_evaluator::eval;
 use crate::vasm_preprocessor::{Line, LineSource};
 use std::collections::BTreeMap;
@@ -13,11 +13,15 @@ fn solve_equs(lines: &[Line]) -> Result<Scope, AssembleError> {
     let line_nums: BTreeMap<usize, i32> = BTreeMap::new();
     for (line_num, line) in lines.iter().enumerate() {
         if let VASMLine::Equ(Label(name), expr) = &line.line {
-            let value = eval(expr, line_num, &line_nums, &scope)
-                .map_err(|e| AssembleError::EquResolveError(line_num, name.to_string(), e))?;
+            let value = eval(expr, line_num, &line_nums, &scope).map_err(|e| {
+                AssembleError::EquResolveError(line.location.clone(), name.to_string(), e)
+            })?;
 
             if let Some(_old_value) = scope.insert(name.clone(), value) {
-                return Err(AssembleError::EquDuplicateError(line_num, name.to_string()));
+                return Err(AssembleError::EquDuplicateError(
+                    line.location.clone(),
+                    name.to_string(),
+                ));
             }
         }
     }
@@ -101,7 +105,7 @@ fn place_labels(
     for (line_num, line) in lines.iter().enumerate() {
         if let VASMLine::Org(_, expr) = &line.line {
             address = eval(expr, line_num, &addresses, &scope)
-                .map_err(|err| AssembleError::OrgResolveError(line_num, err))?;
+                .map_err(|err| AssembleError::OrgResolveError(line.location.clone(), err))?;
             addresses.insert(line_num, address);
         }
 
@@ -167,9 +171,9 @@ pub fn assemble_snippet<T: IntoIterator<Item = String>>(
     lines: T,
 ) -> Result<Vec<u8>, AssembleError> {
     let line_results: Vec<Result<Line, AssembleError>> =
-        LineSource::new("_snippet", lines, |_file| {
+        LineSource::new("<none>", lines, |_file| {
             Err(AssembleError::IncludeError(
-                0,
+                Location::default(),
                 "Including is not supported in assembling snippets".to_string(),
             ))
         })
@@ -239,7 +243,7 @@ fn generate_code<T: IntoIterator<Item = Line>>(lines: T) -> Result<Vec<u8>, Asse
             }
             VASMLine::Instruction(_, opcode, Some(arg)) => {
                 let arg = eval(arg, line_num, &line_addresses, &scope)
-                    .map_err(|err| AssembleError::ArgError(line_num, err))?;
+                    .map_err(|err| AssembleError::ArgError(line.location.clone(), err))?;
                 let len = line_lengths[&line_num] - 1;
                 let instr = (u8::from(*opcode) << 2) + len as u8;
                 code[current_addr - start] = instr;
@@ -255,7 +259,7 @@ fn generate_code<T: IntoIterator<Item = Line>>(lines: T) -> Result<Vec<u8>, Asse
             }
             VASMLine::Db(_, arg) => {
                 let arg = eval(arg, line_num, &line_addresses, &scope)
-                    .map_err(|err| AssembleError::ArgError(line_num, err))?;
+                    .map_err(|err| AssembleError::ArgError(line.location.clone(), err))?;
                 poke_word(&mut code, current_addr - start, arg);
                 current_addr += 3;
             }
@@ -280,7 +284,6 @@ fn generate_code<T: IntoIterator<Item = Line>>(lines: T) -> Result<Vec<u8>, Asse
 mod test {
     use super::AssembleError::*;
     use super::*;
-    use crate::ast::VASMLine;
     use crate::parse_error;
     use crate::parse_error::EvalError::*;
     use crate::vasm_parser::parse_vasm_line;
@@ -288,7 +291,11 @@ mod test {
     fn parse<'a, T: IntoIterator<Item = &'a str>>(lines: T) -> Vec<Line> {
         lines
             .into_iter()
-            .map(|line| parse_vasm_line(line).unwrap().into())
+            .enumerate()
+            .map(|(line_num, line)| Line {
+                line: parse_vasm_line(line).unwrap(),
+                location: line_num.into(),
+            })
             .collect()
     }
 
@@ -336,7 +343,7 @@ mod test {
         assert_eq!(
             solve_equs(&parse(["blah: .equ 5", "foo: .equ banana"])),
             Err(EquResolveError(
-                1,
+                1.into(),
                 "foo".into(),
                 MissingLabel("banana".into())
             ))
@@ -344,14 +351,14 @@ mod test {
         assert_eq!(
             solve_equs(&parse(["blah: .equ foo+3", "foo: .equ 7"])),
             Err(EquResolveError(
-                0,
+                0.into(),
                 "blah".into(),
                 MissingLabel("foo".into())
             ))
         );
         assert_eq!(
             solve_equs(&parse(["blah: .equ 3", "blah: .equ 7"])),
-            Err(EquDuplicateError(1, "blah".into()))
+            Err(EquDuplicateError(1.into(), "blah".into()))
         );
     }
 
@@ -443,11 +450,11 @@ mod test {
     fn test_unresolvable_orgs() {
         assert_eq!(
             place_labels_pass([".org 0xffffff - blah"]),
-            Err(OrgResolveError(0, MissingLabel("blah".into())))
+            Err(OrgResolveError(0.into(), MissingLabel("blah".into())))
         );
         assert_eq!(
             place_labels_pass(["blah: .org blah"]),
-            Err(OrgResolveError(0, MissingLabel("blah".into())))
+            Err(OrgResolveError(0.into(), MissingLabel("blah".into())))
         );
     }
 
@@ -494,7 +501,7 @@ mod test {
         assert_eq!(
             assemble_snippet(["apple"].map(String::from)),
             Err(ParseError(
-                1,
+                1.into(),
                 parse_error::ParseError::InvalidInstruction("apple".into())
             ))
         );
diff --git a/vasm_core/src/vasm_preprocessor.rs b/vasm_core/src/vasm_preprocessor.rs
index f35f713..15b7ed7 100644
--- a/vasm_core/src/vasm_preprocessor.rs
+++ b/vasm_core/src/vasm_preprocessor.rs
@@ -1,5 +1,5 @@
 use crate::ast::{Macro, VASMLine};
-use crate::parse_error::AssembleError;
+use crate::parse_error::{AssembleError, Location};
 use crate::vasm_parser::parse_vasm_line;
 use std::collections::VecDeque;
 use std::iter::Enumerate;
@@ -7,8 +7,7 @@ use std::iter::Enumerate;
 #[derive(Debug, PartialEq, Clone)]
 pub struct Line {
     pub line: VASMLine,
-    pub line_num: usize,
-    pub file: String,
+    pub location: Location,
 }
 
 #[derive(Debug, Clone, PartialEq)]
@@ -48,8 +47,10 @@ impl From<VASMLine> for Line {
     fn from(other: VASMLine) -> Self {
         Line {
             line: other,
-            line_num: 0,
-            file: "<none>".to_string(),
+            location: Location {
+                line_num: 0,
+                file: "<none>".to_string(),
+            },
         }
     }
 }
@@ -76,7 +77,7 @@ impl<T: IntoIterator<Item = String>, F: Fn(String) -> Result<T, AssembleError>>
             // Try and parse it
             return match parse_vasm_line(line.as_str()) {
                 // We failed to parse it
-                Err(err) => Some(Err(AssembleError::ParseError(self.current_line, err))),
+                Err(err) => Some(Err(AssembleError::ParseError(self.current_location(), err))),
 
                 // It's a macro, so do it and then try again
                 Ok(VASMLine::Macro(mac)) => {
@@ -92,8 +93,10 @@ impl<T: IntoIterator<Item = String>, F: Fn(String) -> Result<T, AssembleError>>
 
                 Ok(normal_line) => Some(Ok(Line {
                     line: normal_line,
-                    line_num: self.current_line,
-                    file: self.filename_stack.last().unwrap().clone(),
+                    location: Location {
+                        line_num: self.current_line,
+                        file: self.filename_stack.last().unwrap().clone(),
+                    },
                 })),
             };
         }
@@ -122,8 +125,10 @@ impl<T: IntoIterator<Item = String>, F: Fn(String) -> Result<T, AssembleError>>
     fn emit(&mut self, line: String) {
         self.generated_lines.push_back(Line {
             line: parse_vasm_line(line.as_str()).unwrap(),
-            line_num: self.current_line,
-            file: self.filename_stack.last().unwrap().clone(),
+            location: Location {
+                line_num: self.current_line,
+                file: self.filename_stack.last().unwrap().clone(),
+            },
         })
     }
 
@@ -132,6 +137,13 @@ impl<T: IntoIterator<Item = String>, F: Fn(String) -> Result<T, AssembleError>>
         format!("__gensym_{}", self.current_sym)
     }
 
+    fn current_location(&self) -> Location {
+        Location {
+            line_num: self.current_line,
+            file: self.filename_stack.last().unwrap().clone(),
+        }
+    }
+
     fn handle_macro(&mut self, mac: Macro) -> Option<AssembleError> {
         match mac {
             Macro::Include(file) => {
@@ -166,7 +178,7 @@ impl<T: IntoIterator<Item = String>, F: Fn(String) -> Result<T, AssembleError>>
                     self.emit(format!("jmpr @{}", new_end));
                     self.emit(format!("{}:", old_end));
                 } else {
-                    return Some(AssembleError::MacroError(self.current_line));
+                    return Some(AssembleError::MacroError(self.current_location()));
                 }
             }
 
@@ -188,7 +200,7 @@ impl<T: IntoIterator<Item = String>, F: Fn(String) -> Result<T, AssembleError>>
                     };
                     self.emit(format!("{} @{}", instr, after));
                 } else {
-                    return Some(AssembleError::MacroError(self.current_line));
+                    return Some(AssembleError::MacroError(self.current_location()));
                 }
             }
 
@@ -198,7 +210,7 @@ impl<T: IntoIterator<Item = String>, F: Fn(String) -> Result<T, AssembleError>>
                     self.emit(format!("jmpr @{}", start));
                     self.emit(format!("{}:", after));
                 }
-                _ => return Some(AssembleError::MacroError(self.current_line)),
+                _ => return Some(AssembleError::MacroError(self.current_location())),
             },
         }
         None
@@ -229,9 +241,11 @@ mod tests {
         assert_eq!(
             src.next(),
             Some(Ok(Line {
-                line_num: 1,
-                file: "blah".to_string(),
-                line: VASMLine::Instruction(None, Add, None)
+                line: VASMLine::Instruction(None, Add, None),
+                location: Location {
+                    line_num: 1,
+                    file: "blah".to_string(),
+                }
             }))
         );
         assert_eq!(src.next(), None);
@@ -246,14 +260,18 @@ mod tests {
             src.collect::<Vec<Result<Line, AssembleError>>>(),
             vec![
                 Ok(Line {
-                    line_num: 1,
-                    file: "foo".to_string(),
-                    line: VASMLine::Instruction(None, Sub, None)
+                    line: VASMLine::Instruction(None, Sub, None),
+                    location: Location {
+                        line_num: 1,
+                        file: "foo".to_string(),
+                    }
                 }),
                 Ok(Line {
-                    line_num: 2,
-                    file: "blah".to_string(),
-                    line: VASMLine::Instruction(None, Add, None)
+                    line: VASMLine::Instruction(None, Add, None),
+                    location: Location {
+                        line_num: 2,
+                        file: "blah".to_string(),
+                    }
                 })
             ]
         );