diff --git a/CHANGELOG.md b/CHANGELOG.md
index 394257c..9dd10c6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
     when processing large messages in certain configurations.
 *   Document requirement to keep `--max-message-size` setting in sync with
     `spamc`’s `--max-size` setting.
+*   Remove overly strict validation of command-line options.
 *   Properly specify minimal dependency versions in `Cargo.toml`.
 *   Document minimum supported Rust version 1.42.0.
 
diff --git a/Cargo.lock b/Cargo.lock
index 4465c04..11f4717 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -136,9 +136,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.5.2"
+version = "1.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13bd41f508810a131401606d54ac32a467c97172d74ba7662562ebba5ad07fa0"
+checksum = "af8b08b04175473088b46763e51ee54da5f9a164bc162f615b91bc179dbf15a3"
 
 [[package]]
 name = "pkg-config"
@@ -157,9 +157,9 @@ dependencies = [
 
 [[package]]
 name = "quote"
-version = "1.0.8"
+version = "1.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "991431c3519a3f36861882da93630ce66b52918dcf1b8e2fd66b397fc96f28df"
+checksum = "c3d0b9745dc2debf507c8422de05d7226cc1f0644216dfdfead988f9b1ab32a7"
 dependencies = [
  "proc-macro2",
 ]