diff --git a/action.yml b/action.yml
index 4097d352..b3f3bd63 100644
--- a/action.yml
+++ b/action.yml
@@ -6,6 +6,10 @@ inputs:
     description: Swift version to configure
     required: true
     default: '6.1.0'
+  soft-fail-version-check:
+    description: 'If true, unknown Swift versions will only warn instead of error'
+    required: false
+    default: 'false'
 outputs:
   version:
     description: The full Swift version that was configured
diff --git a/dist/index.js b/dist/index.js
index d94c7e24..dd3509de 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -459,6 +459,7 @@ exports.verify = exports.swiftPackage = void 0;
 const semver = __importStar(__nccwpck_require__(1383));
 const core = __importStar(__nccwpck_require__(2186));
 const os_1 = __nccwpck_require__(1855);
+const softFailVersionCheck = core.getInput("soft-fail-version-check").toLowerCase() === "true";
 const VERSIONS_LIST = [
     ["6.1.0", [os_1.OS.MacOS, os_1.OS.Ubuntu]],
     ["6.0.3", [os_1.OS.MacOS, os_1.OS.Ubuntu]],
@@ -575,6 +576,10 @@ function verify(version, system) {
     let systemVersions = AVAILABLE_VERSIONS.filter(([_, os]) => os.includes(system.os)).map(([version, _]) => version);
     let matchingVersion = evaluateVersions(systemVersions, version);
     if (matchingVersion === null) {
+        if (softFailVersionCheck) {
+            core.warning(`Swift version "${version}" not in the list of tested versions; proceeding anyway because soft-fail-version-check is enabled.`);
+            return version;
+        }
         throw new Error(`Version "${version}" is not available`);
     }
     core.debug(`Found matching version ${matchingVersion}`);
diff --git a/src/swift-versions.ts b/src/swift-versions.ts
index 7394f926..7bef0656 100644
--- a/src/swift-versions.ts
+++ b/src/swift-versions.ts
@@ -2,6 +2,9 @@ import * as semver from "semver";
 import * as core from "@actions/core";
 import { System, OS } from "./os";
 
+const softFailVersionCheck =
+  core.getInput("soft-fail-version-check").toLowerCase() === "true";
+
 const VERSIONS_LIST: [string, OS[]][] = [
   ["6.1.0", [OS.MacOS, OS.Ubuntu]],
   ["6.0.3", [OS.MacOS, OS.Ubuntu]],
@@ -136,6 +139,12 @@ export function verify(version: string, system: System) {
 
   let matchingVersion = evaluateVersions(systemVersions, version);
   if (matchingVersion === null) {
+    if (softFailVersionCheck) {
+      core.warning(
+        `Swift version "${version}" not in the list of tested versions; proceeding anyway because soft-fail-version-check is enabled.`
+      );
+      return version;
+    }
     throw new Error(`Version "${version}" is not available`);
   }