diff --git a/src/libcretonne/Cargo.toml b/src/libcretonne/Cargo.toml
index 5d3a9511e6..174fb2e0bf 100644
--- a/src/libcretonne/Cargo.toml
+++ b/src/libcretonne/Cargo.toml
@@ -13,4 +13,7 @@ name = "cretonne"
 path = "lib.rs"
 
 [dependencies]
-regex = "0.1.71"
+# It is a goal of the cretonne crate to have minimal external dependencies.
+# Please don't add any unless they are essential to the task of creating binary
+# machine code. Integration tests that need external dependencies can be
+# accomodated in src/tools/tests.
diff --git a/src/libcretonne/verifier.rs b/src/libcretonne/verifier.rs
index d58283e3ae..2b544967e2 100644
--- a/src/libcretonne/verifier.rs
+++ b/src/libcretonne/verifier.rs
@@ -165,22 +165,18 @@ impl<'a> Verifier<'a> {
 
 #[cfg(test)]
 mod tests {
-    extern crate regex;
-
     use super::*;
     use ir::Function;
     use ir::instructions::{InstructionData, Opcode};
     use ir::types;
-    use self::regex::Regex;
 
     macro_rules! assert_err_with_msg {
         ($e:expr, $msg:expr) => (
-            let err_re = Regex::new($msg).unwrap();
             match $e {
                 Ok(_) => { panic!("Expected an error!") },
-                Err(Error { location, message } ) => {
-                    if !err_re.is_match(&message) {
-                       panic!(format!("'{}' did not contain the pattern '{}'", message, $msg));
+                Err(Error { message, .. } ) => {
+                    if !message.contains($msg) {
+                       panic!(format!("'{}' did not contain the substring '{}'", message, $msg));
                     }
                 }
             }
diff --git a/src/tools/Cargo.lock b/src/tools/Cargo.lock
index 2aca3c591b..50576fd02b 100644
--- a/src/tools/Cargo.lock
+++ b/src/tools/Cargo.lock
@@ -6,8 +6,6 @@ dependencies = [
  "cretonne-reader 0.0.0",
  "docopt 0.6.80 (registry+https://github.com/rust-lang/crates.io-index)",
  "filecheck 0.0.0",
- "glob 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex 0.1.71 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -22,9 +20,6 @@ dependencies = [
 [[package]]
 name = "cretonne"
 version = "0.0.0"
-dependencies = [
- "regex 0.1.71 (registry+https://github.com/rust-lang/crates.io-index)",
-]
 
 [[package]]
 name = "cretonne-reader"
@@ -50,11 +45,6 @@ dependencies = [
  "regex 0.1.71 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "glob"
-version = "0.2.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "kernel32-sys"
 version = "0.2.2"
diff --git a/src/tools/Cargo.toml b/src/tools/Cargo.toml
index ba465f7d0e..b4572f9f49 100644
--- a/src/tools/Cargo.toml
+++ b/src/tools/Cargo.toml
@@ -15,5 +15,3 @@ cretonne-reader = { path = "../libreader" }
 filecheck = { path = "../libfilecheck" }
 docopt = "0.6.80"
 rustc-serialize = "0.3.19"
-regex = "0.1.71"
-glob = "0.2.11"