diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1190f72a..58ef9b7b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -29,6 +29,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - `libcnb`:
   - Made `Target` (the type of `DetectContext::target` and `BuildContext::target`) public. ([#815](https://github.com/heroku/libcnb.rs/pull/815))
+- `libcnb-test`
+  - Added the macro `assert_contains_match!` for testing if a value contains a regular expression match.
+  - Added the macro `assert_not_contains_match!` for testing if a value does not contain a regular expression match.
 
 ### Changed
 
diff --git a/libcnb-test/Cargo.toml b/libcnb-test/Cargo.toml
index 8985d4d5..787115be 100644
--- a/libcnb-test/Cargo.toml
+++ b/libcnb-test/Cargo.toml
@@ -20,6 +20,7 @@ fs_extra = "1.3.0"
 libcnb-common.workspace = true
 libcnb-data.workspace = true
 libcnb-package.workspace = true
+regex = "1.10.4"
 tempfile = "3.10.1"
 thiserror = "1.0.59"
 
diff --git a/libcnb-test/src/lib.rs b/libcnb-test/src/lib.rs
index 15002761..8f78fff4 100644
--- a/libcnb-test/src/lib.rs
+++ b/libcnb-test/src/lib.rs
@@ -27,3 +27,5 @@ use indoc as _;
 use libcnb as _;
 #[cfg(test)]
 use ureq as _;
+// This dependency is used by the `assert_not_contains` and `assert_not_contains_match` macros
+use regex as _;
diff --git a/libcnb-test/src/macros.rs b/libcnb-test/src/macros.rs
index 830a1056..317e89d6 100644
--- a/libcnb-test/src/macros.rs
+++ b/libcnb-test/src/macros.rs
@@ -141,6 +141,116 @@ value (escaped): `{:?}`: {}"#,
     }};
 }
 
+/// Asserts that `left` contains the `right` pattern (regular expression).
+///
+/// Commonly used when asserting `pack` output in integration tests. Expands to a regular
+/// expression match test and logs `left` (in unescaped and escaped form) as well as `right`
+/// on failure.
+///
+/// Multi-line mode is automatically enabled on regular expressions. If this is not what you
+/// want it can be disabled by adding `(?-m)` to the start of your pattern.
+///
+/// # Example
+///
+/// ```
+/// use libcnb_test::assert_contains_match;
+///
+/// let output = "Hello World!\nHello Integration Test!";
+/// assert_contains_match!(output, "Test!$");
+/// ```
+#[macro_export]
+macro_rules! assert_contains_match {
+    ($left:expr, $right:expr $(,)?) => {{
+        let regex = regex::Regex::new(&format!("(?m){}", $right)).expect("should be a valid regex");
+        if !regex.is_match(&$left) {
+            ::std::panic!(
+                r#"assertion failed: `(left matches right pattern)`
+left (unescaped):
+{}
+
+left (escaped): `{:?}`
+right: `{:?}`"#,
+                $left,
+                $left,
+                regex
+            )
+        }
+    }};
+
+    ($left:expr, $right:expr, $($arg:tt)+) => {{
+        let regex = regex::Regex::new(&format!("(?m){}", $right)).expect("should be a valid regex");
+        if !regex.is_match(&$left) {
+            ::std::panic!(
+                r#"assertion failed: `(left matches right pattern)`
+left (unescaped):
+{}
+
+left (escaped): `{:?}`
+right: `{:?}`: {}"#,
+                $left,
+                $left,
+                regex,
+                ::core::format_args!($($arg)+)
+            )
+        }
+    }};
+}
+
+/// Asserts that `left` does not contain the `right` pattern (regular expression).
+///
+/// Commonly used when asserting `pack` output in integration tests. Expands to a regular
+/// expression match test and logs `left` (in unescaped and escaped form) as well as `right`
+/// on failure.
+///
+/// Multi-line mode is automatically enabled on regular expressions. If this is not what you
+/// want it can be disabled by adding `(?-m)` to the start of your pattern.
+///
+/// # Example
+///
+/// ```
+/// use libcnb_test::assert_not_contains_match;
+///
+/// let output = "Hello World!\nHello Integration Test!";
+/// assert_not_contains_match!(output, "^Test!");
+/// ```
+#[macro_export]
+macro_rules! assert_not_contains_match {
+    ($left:expr, $right:expr $(,)?) => {{
+        let regex = regex::Regex::new(&format!("(?m){}", $right)).expect("should be a valid regex");
+        if regex.is_match(&$left) {
+            ::std::panic!(
+                r#"assertion failed: `(left does not match right pattern)`
+left (unescaped):
+{}
+
+left (escaped): `{:?}`
+right: `{:?}`"#,
+                $left,
+                $left,
+                regex
+            )
+        }
+    }};
+
+    ($left:expr, $right:expr, $($arg:tt)+) => {{
+        let regex = regex::Regex::new(&format!("(?m){}", $right)).expect("should be a valid regex");
+        if regex.is_match(&$left) {
+            ::std::panic!(
+                r#"assertion failed: `(left does not match right pattern)`
+left (unescaped):
+{}
+
+left (escaped): `{:?}`
+right: `{:?}`: {}"#,
+                $left,
+                $left,
+                regex,
+                ::core::format_args!($($arg)+)
+            )
+        }
+    }};
+}
+
 #[cfg(test)]
 mod tests {
     #[test]
@@ -332,4 +442,198 @@ value (escaped): `\"Hello World!\\nFoo\\nBar\\nBaz\"`: Greeting must be empty!")
     fn empty_multiline_failure_with_args() {
         assert_empty!("Hello World!\nFoo\nBar\nBaz", "Greeting must be empty!");
     }
+
+    #[test]
+    fn contains_match_simple() {
+        assert_contains_match!("Hello World!", "(?i)hello world!");
+    }
+
+    #[test]
+    fn contains_match_simple_with_args() {
+        assert_contains_match!("Hello World!", "(?i)hello world!", "World must be greeted");
+    }
+
+    #[test]
+    #[should_panic(expected = "assertion failed: `(left matches right pattern)`
+left (unescaped):
+foo
+
+left (escaped): `\"foo\"`
+right: `Regex(\"(?m)bar\")`")]
+    fn contains_match_simple_failure() {
+        assert_contains_match!("foo", "bar");
+    }
+
+    #[test]
+    #[should_panic(expected = "assertion failed: `(left matches right pattern)`
+left (unescaped):
+Hello World!
+
+left (escaped): `\"Hello World!\"`
+right: `Regex(\"(?m)(?-i)world\")`: World must be case-sensitively greeted!")]
+    fn contains_match_simple_failure_with_args() {
+        assert_contains_match!(
+            "Hello World!",
+            "(?-i)world",
+            "World must be case-sensitively greeted!"
+        );
+    }
+
+    #[test]
+    fn contains_match_multiline() {
+        assert_contains_match!("Hello World!\nFoo\nBar\nBaz", "^Bar$");
+    }
+
+    #[test]
+    #[should_panic(expected = "assertion failed: `(left matches right pattern)`
+left (unescaped):
+Hello World!
+Foo
+Bar
+Baz
+
+left (escaped): `\"Hello World!\\nFoo\\nBar\\nBaz\"`
+right: `Regex(\"(?m)Eggs\")`")]
+    fn contains_match_multiline_failure() {
+        assert_contains_match!("Hello World!\nFoo\nBar\nBaz", "Eggs");
+    }
+
+    #[test]
+    #[should_panic(expected = "assertion failed: `(left matches right pattern)`
+left (unescaped):
+Hello World!
+Foo
+Bar
+Baz
+
+left (escaped): `\"Hello World!\\nFoo\\nBar\\nBaz\"`
+right: `Regex(\"(?m)Eggs\")`: We need eggs!")]
+    fn contains_match_multiline_failure_with_args() {
+        assert_contains_match!("Hello World!\nFoo\nBar\nBaz", "Eggs", "We need eggs!");
+    }
+
+    #[test]
+    #[should_panic(expected = "should be a valid regex: Syntax(
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+regex parse error:
+    (?m)(unclosed group
+        ^
+error: unclosed group
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+)")]
+    fn contains_match_with_invalid_regex() {
+        assert_contains_match!("Hello World!", "(unclosed group");
+    }
+
+    #[test]
+    #[should_panic(expected = "should be a valid regex: Syntax(
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+regex parse error:
+    (?m)(unclosed group
+        ^
+error: unclosed group
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+)")]
+    fn contains_match_with_invalid_regex_and_args() {
+        assert_contains_match!("Hello World!", "(unclosed group", "This should fail.");
+    }
+
+    #[test]
+    fn not_contains_match_simple() {
+        assert_not_contains_match!("Hello World!", "^World");
+    }
+
+    #[test]
+    fn not_contains_match_simple_with_args() {
+        assert_not_contains_match!("Hello World!", "^World", "World must not be at the start!");
+    }
+
+    #[test]
+    #[should_panic(expected = "assertion failed: `(left does not match right pattern)`
+left (unescaped):
+foobar
+
+left (escaped): `\"foobar\"`
+right: `Regex(\"(?m)bar\")`")]
+    fn not_contains_match_simple_failure() {
+        assert_not_contains_match!("foobar", "bar");
+    }
+
+    #[test]
+    #[should_panic(expected = "assertion failed: `(left does not match right pattern)`
+left (unescaped):
+Hello Germany!
+
+left (escaped): `\"Hello Germany!\"`
+right: `Regex(\"(?m)Germany!$\")`: Germany must not be greeted!")]
+    fn not_contains_match_simple_failure_with_args() {
+        assert_not_contains_match!(
+            "Hello Germany!",
+            "Germany!$",
+            "Germany must not be greeted!"
+        );
+    }
+
+    #[test]
+    fn not_contains_match_multiline() {
+        assert_not_contains_match!("Hello World!\nFoo\nBar\nBaz", "^Germany$");
+    }
+
+    #[test]
+    #[should_panic(expected = "assertion failed: `(left does not match right pattern)`
+left (unescaped):
+Hello World!
+Foo
+Bar
+Baz
+
+left (escaped): `\"Hello World!\\nFoo\\nBar\\nBaz\"`
+right: `Regex(\"(?m)^Bar$\")`")]
+    fn not_contains_match_multiline_failure() {
+        assert_not_contains_match!("Hello World!\nFoo\nBar\nBaz", "^Bar$");
+    }
+
+    #[test]
+    #[should_panic(expected = "assertion failed: `(left does not match right pattern)`
+left (unescaped):
+Hello Eggs!
+Foo
+Bar
+Baz
+
+left (escaped): `\"Hello Eggs!\\nFoo\\nBar\\nBaz\"`
+right: `Regex(\"(?m)Eggs!$\")`: We must not have eggs!")]
+    fn not_contains_match_multiline_failure_with_args() {
+        assert_not_contains_match!(
+            "Hello Eggs!\nFoo\nBar\nBaz",
+            "Eggs!$",
+            "We must not have eggs!"
+        );
+    }
+
+    #[test]
+    #[should_panic(expected = "should be a valid regex: Syntax(
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+regex parse error:
+    (?m)(unclosed group
+        ^
+error: unclosed group
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+)")]
+    fn not_contains_match_with_invalid_regex() {
+        assert_not_contains_match!("Hello World!", "(unclosed group");
+    }
+
+    #[test]
+    #[should_panic(expected = "should be a valid regex: Syntax(
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+regex parse error:
+    (?m)(unclosed group
+        ^
+error: unclosed group
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+)")]
+    fn not_contains_match_with_invalid_regex_and_args() {
+        assert_not_contains_match!("Hello World!", "(unclosed group", "This will fail");
+    }
 }