diff --git a/Cargo.lock b/Cargo.lock
index 040abe6..8bc6777 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,15 +2,6 @@
 # It is not intended for manual editing.
 version = 3
 
-[[package]]
-name = "aho-corasick"
-version = "0.7.18"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e37cfd5e7657ada45f742d6e99ca5788580b5c529dc78faf11ece6dc702656f"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "ansi_term"
 version = "0.11.0"
@@ -147,7 +138,6 @@ checksum = "308cc39be01b73d0d18f82a0e7b2a3df85245f84af96fdddc5d202d27e47b86a"
 name = "opml"
 version = "1.1.1"
 dependencies = [
- "regex",
  "serde",
  "strong-xml",
  "thiserror",
@@ -209,29 +199,12 @@ dependencies = [
  "proc-macro2",
 ]
 
-[[package]]
-name = "regex"
-version = "1.5.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d07a8629359eb56f1e2fb1652bb04212c072a87ba68546a04065d525673ac461"
-dependencies = [
- "aho-corasick",
- "memchr",
- "regex-syntax",
-]
-
 [[package]]
 name = "regex-automata"
 version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6c230d73fb8d8c1b9c0b3135c5142a8acee3a0558fb8db5cf1cb65f8d7862132"
 
-[[package]]
-name = "regex-syntax"
-version = "0.6.25"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f497285884f3fcff424ffc933e56d7cbca511def0c9831a7f9b5f6153e3cc89b"
-
 [[package]]
 name = "ryu"
 version = "1.0.5"
diff --git a/opml_api/Cargo.toml b/opml_api/Cargo.toml
index 6c7a75c..a7e0ef0 100644
--- a/opml_api/Cargo.toml
+++ b/opml_api/Cargo.toml
@@ -15,7 +15,6 @@ keywords = ["xml", "opml"]
 path = "source/lib.rs"
 
 [dependencies]
-regex = "1.5.4"
 strong-xml = "0.6.3"
 thiserror = "1.0.29"
 
diff --git a/opml_api/source/lib.rs b/opml_api/source/lib.rs
index 9c64716..7650b99 100644
--- a/opml_api/source/lib.rs
+++ b/opml_api/source/lib.rs
@@ -29,7 +29,6 @@
 //! To create an OPML document from scratch, use [`OPML::default()`] or the good
 //! old `OPML { /* ... */ }` syntax.
 
-use regex::Regex;
 use serde::{Deserialize, Serialize};
 use strong_xml::{XmlRead, XmlWrite};
 use thiserror::Error;
@@ -105,16 +104,11 @@ impl OPML {
   pub fn from_str(xml: &str) -> Result<Self, Error> {
     let opml = <OPML as XmlRead>::from_str(xml)?;
 
-    let version = &opml.version;
-
     // SPEC: The version attribute is a version string, of the form, x.y, where
     // x and y are both numeric strings.
-    let valid_version_regex = Regex::new(r"^\d+\.\d+$").unwrap();
     let valid_versions = vec!["1.0", "1.1", "2.0"];
 
-    if !valid_version_regex.is_match(version)
-      || !valid_versions.contains(&version.as_str())
-    {
+    if !valid_versions.contains(&opml.version.as_str()) {
       return Err(Error::UnsupportedVersion(opml.version));
     }