diff --git a/integration-tests/single-check-with-variable.sh b/integration-tests/single-check-with-variable.sh
new file mode 100644
index 0000000..8039038
--- /dev/null
+++ b/integration-tests/single-check-with-variable.sh
@@ -0,0 +1,4 @@
+# RUN: sh @file
+
+# CHECK: hello @file
+echo hello $0
diff --git a/src/model.rs b/src/model.rs
index fdd4792..5f5dd2a 100644
--- a/src/model.rs
+++ b/src/model.rs
@@ -53,6 +53,7 @@ pub struct TextPattern {
 /// A component in a text pattern.
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub enum PatternComponent {
+    Constant(String),
     Text(String),
     Variable(String),
     Regex(String),
@@ -198,6 +199,7 @@ impl fmt::Display for TextPattern {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         for component in self.components.iter() {
             match *component {
+                PatternComponent::Constant(ref constant) => write!(fmt, "@{}", constant)?,
                 PatternComponent::Text(ref text) => write!(fmt, "{}", text)?,
                 PatternComponent::Variable(ref name) => write!(fmt, "$${}", name)?,
                 PatternComponent::Regex(ref regex) => write!(fmt, "[[{}]]", regex)?,
diff --git a/src/parse.rs b/src/parse.rs
index 7772f6b..3e73964 100644
--- a/src/parse.rs
+++ b/src/parse.rs
@@ -123,8 +123,15 @@ pub fn text_pattern(s: &str) -> TextPattern {
                     Some(name) => components.push(PatternComponent::NamedRegex { name: name.to_owned(), regex: regex.to_owned() }),
                     None => components.push(PatternComponent::Regex(regex.to_owned())),
                 }
+            }
+            // Constants.
+            (Some('@'), _) => {
+                complete_text(&mut current_text, &mut components);
 
-            },
+                let name: String = chars.clone().take_while(|c| c.is_alphanumeric()).collect();
+                chars.nth(name.len() - 1); // Skip the constant name.
+                components.push(PatternComponent::Constant(name));
+            }
             (Some(c), _) => {
                 current_text.push(c);
             },
@@ -177,39 +184,37 @@ pub fn possible_command(string: &str, line: u32)
     }
 }
 
-#[cfg(tes)]
+#[cfg(test)]
 mod test {
     use super::*;
-    use std::collections::HashMap;
 
     #[test]
     fn parses_single_text() {
-        assert_eq!(text_pattern("hello world"),
-                   "hello world");
+        assert_eq!(format!("{}", text_pattern("hello world")), "hello world");
     }
 
     #[test]
     fn correctly_escapes_text() {
-        assert_eq!(text_pattern("hello()").as_str(),
-                   "hello\\(\\)");
+        assert_eq!(format!("{}", text_pattern("hello\\(\\)")), "hello\\(\\)");
     }
 
     #[test]
     fn correctly_picks_up_single_regex() {
-        assert_eq!(text_pattern("[[\\d]]").as_str(),
-                   "\\d");
+        assert_eq!(format!("{}", text_pattern("[[\\d]]")), "[[\\d]]");
     }
 
     #[test]
     fn correctly_picks_up_regex_between_text() {
-        assert_eq!(text_pattern("1[[\\d]]3").as_str(),
-                   "1\\d3");
+        assert_eq!(format!("{}", text_pattern("1[[\\d]]3")), "1[[\\d]]3");
     }
 
     #[test]
     fn correctly_picks_up_named_regex() {
-        assert_eq!(text_pattern("[[num:\\d]]").as_str(),
-                   "(?P<num>\\d)");
+        assert_eq!(format!("{}", text_pattern("[[num:\\d]]")), "[[num:\\d]]");
     }
-}
 
+    #[test]
+    fn parses_constant() {
+        assert_eq!(format!("{}", text_pattern("@constant")), "@constant");
+    }
+}
diff --git a/src/vars/resolve.rs b/src/vars/resolve.rs
index 6d284b1..eb11997 100644
--- a/src/vars/resolve.rs
+++ b/src/vars/resolve.rs
@@ -25,7 +25,7 @@ pub fn text_pattern(pattern: &TextPattern, config: &Config,
                     variables: &mut Variables) -> Regex {
     let regex_parts: Vec<_> = pattern.components.iter().map(|comp| match *comp {
         PatternComponent::Text(ref text) => regex::escape(text),
-        PatternComponent::Variable(ref name) => {
+        PatternComponent::Constant(ref name) | PatternComponent::Variable(ref name) => {
             // FIXME: proper error handling.
             let value = config.lookup_variable(name, variables);