diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7993bf3..cefe2cf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,7 +5,7 @@
 *   Invoke `spamc` using the absolute path `/usr/bin/spamc`. To customise this,
     set the environment variable `SPAMASSASSIN_MILTER_SPAMC` to the desired path
     when building the application.
-*   The minimum supported Rust version is now 1.46.0.
+*   Update dependencies.
 
 ## 0.1.6 (2021-05-17)
 
diff --git a/README.md b/README.md
index 576cf78..b060c72 100644
--- a/README.md
+++ b/README.md
@@ -61,7 +61,7 @@ recently, `miltertest` had a serious bug that prevents most integration tests in
 this package from completing; make sure you use an up-to-date version of
 `miltertest`.)
 
-The minimum supported Rust version is 1.46.0.
+The minimum supported Rust version is 1.42.0.
 
 [Rust]: https://www.rust-lang.org
 
diff --git a/src/client.rs b/src/client.rs
index 4248c48..1fe6797 100644
--- a/src/client.rs
+++ b/src/client.rs
@@ -26,11 +26,6 @@ pub struct Spamc {
 }
 
 impl Spamc {
-    const SPAMC_PROGRAM: &'static str = match option_env!("SPAMASSASSIN_MILTER_SPAMC") {
-        Some(p) => p,
-        None => "/usr/bin/spamc",
-    };
-
     pub fn new(spamc_args: &'static [String]) -> Self {
         Self {
             spamc_args,
@@ -42,9 +37,11 @@ impl Spamc {
 
 impl Process for Spamc {
     fn connect(&mut self) -> Result<()> {
+        let spamc_program = option_env!("SPAMASSASSIN_MILTER_SPAMC").unwrap_or("/usr/bin/spamc");
+
         // `Command::spawn` always succeeds when `spamc` can be invoked, even if
         // logically the command is invalid, eg if it uses non-existing options.
-        let mut spamc = Command::new(Spamc::SPAMC_PROGRAM)
+        let mut spamc = Command::new(spamc_program)
             .args(self.spamc_args)
             .stdin(Stdio::piped())
             .stdout(Stdio::piped())