diff --git a/include/uzuki2/Version.hpp b/include/uzuki2/Version.hpp
index 841185a..55ab9dc 100644
--- a/include/uzuki2/Version.hpp
+++ b/include/uzuki2/Version.hpp
@@ -1,9 +1,6 @@
 #ifndef UZUKI2_VERSIONED_BASE_HPP
 #define UZUKI2_VERSIONED_BASE_HPP
 
-#include <string>
-#include <cstring>
-
 /**
  * @file Version.hpp
  * @brief Version-related definitions.
@@ -63,54 +60,6 @@ struct Version {
     }
 };
 
-/**
- * @cond
- */
-inline Version parse_version_string(const std::string& version_string) {
-    int major = 0, minor = 0;
-    size_t i = 0, end = version_string.size();
-
-    if (version_string.empty()) {
-        throw std::runtime_error("version string is empty");
-    }
-    if (version_string[i] == '0') {
-        throw std::runtime_error("invalid version string '" + version_string + "' has leading zeros in its major version");
-    }
-    while (i < end && version_string[i] != '.') {
-        if (!std::isdigit(version_string[i])) {
-            throw std::runtime_error("invalid version string '" + version_string + "' contains non-digit characters");
-        }
-        major *= 10;
-        major += version_string[i] - '0';
-        ++i;
-    }
-
-    if (i == end) {
-        throw std::runtime_error("version string '" + version_string + "' is missing a minor version");
-    }
-    ++i; // get past the period and check again.
-    if (i == end) {
-        throw std::runtime_error("version string '" + version_string + "' is missing a minor version");
-    }
-
-    if (version_string[i] == '0' && i + 1 < end) {
-        throw std::runtime_error("invalid version string '" + version_string + "' has leading zeros in its minor version");
-    }
-    while (i < end) {
-        if (!std::isdigit(version_string[i])) {
-            throw std::runtime_error("invalid version string '" + version_string + "' contains non-digit characters");
-        }
-        minor *= 10;
-        minor += version_string[i] - '0';
-        ++i;
-    }
-
-    return Version(major, minor);
-}
-/**
- * @cond
- */
-
 }
 
 #endif
diff --git a/include/uzuki2/parse_hdf5.hpp b/include/uzuki2/parse_hdf5.hpp
index 200c7b7..6f0e5ff 100644
--- a/include/uzuki2/parse_hdf5.hpp
+++ b/include/uzuki2/parse_hdf5.hpp
@@ -460,7 +460,9 @@ ParsedList parse(const H5::Group& handle, Externals ext) {
     Version version;
     if (handle.attrExists("uzuki_version")) {
         auto ver_str = ritsuko::hdf5::load_scalar_string_attribute(handle, "uzuki_version");
-        version = parse_version_string(ver_str);
+        auto vraw = ritsuko::parse_version_string(ver_str.c_str(), ver_str.size(), /* skip_patch = */ true);
+        version.major = vraw.major;
+        version.minor = vraw.minor;
     }
 
     ExternalTracker etrack(std::move(ext));
diff --git a/include/uzuki2/parse_json.hpp b/include/uzuki2/parse_json.hpp
index b380c92..99303ca 100644
--- a/include/uzuki2/parse_json.hpp
+++ b/include/uzuki2/parse_json.hpp
@@ -434,8 +434,10 @@ ParsedList parse(byteme::Reader& reader, Externals ext, Options options = Option
             if (vIt->second->type() != millijson::STRING) {
                 throw std::runtime_error("expected a string in 'version'");
             }
-            auto vptr = static_cast<const millijson::String*>(vIt->second.get());
-            version = parse_version_string(vptr->value);
+            const auto& vstr = static_cast<const millijson::String*>(vIt->second.get())->value;
+            auto vraw = ritsuko::parse_version_string(vstr.c_str(), vstr.size(), /* skip_patch = */ true);
+            version.major = vraw.major;
+            version.minor = vraw.minor;
         }
     }
 
diff --git a/tests/src/misc.cpp b/tests/src/misc.cpp
index 90ee28e..ebdf5d1 100644
--- a/tests/src/misc.cpp
+++ b/tests/src/misc.cpp
@@ -148,44 +148,3 @@ TEST(JsonFileTest, CheckMethods) {
 TEST(JsonFileTest, CheckVersion) {
     expect_json_error("{ version: true }", "expected a string");
 }
-
-TEST(VersionParsing, Basic) {
-    {
-        auto v = uzuki2::parse_version_string("1.0");
-        EXPECT_EQ(v.major, 1);
-        EXPECT_EQ(v.minor, 0);
-    }
-
-    {
-        auto v = uzuki2::parse_version_string("1.12");
-        EXPECT_EQ(v.major, 1);
-        EXPECT_EQ(v.minor, 12);
-    }
-
-    {
-        auto v = uzuki2::parse_version_string("123.456");
-        EXPECT_EQ(v.major, 123);
-        EXPECT_EQ(v.minor, 456);
-    }
-}
-
-static void expect_version_error(std::string version, std::string msg) {
-    EXPECT_ANY_THROW({
-        try {
-            uzuki2::parse_version_string(version);
-        } catch (std::exception& e) {
-            EXPECT_THAT(e.what(), ::testing::HasSubstr(msg));
-            throw;
-        }
-    });
-}
-
-TEST(VersionParsing, Errors) {
-    expect_version_error("", "empty");
-    expect_version_error("0.1", "leading zeros");
-    expect_version_error("a.1", "non-digit");
-    expect_version_error("1", "minor version");
-    expect_version_error("1.", "minor version");
-    expect_version_error("1.01", "leading zeros");
-    expect_version_error("1.a", "non-digit");
-}