diff --git a/src/common/config.ts b/src/common/config.ts
index a4ff9c11..9fa78ec0 100644
--- a/src/common/config.ts
+++ b/src/common/config.ts
@@ -89,7 +89,7 @@ const OPTIONS = {
         "greedy-arrays": true,
         "short-option-groups": false,
     },
-};
+} as const;
 
 function isConnectionSpecifier(arg: string | undefined): boolean {
     return (
@@ -187,12 +187,19 @@ function getExportsPath(): string {
 // are prefixed with `MDB_MCP_` and the keys match the UserConfig keys, but are converted
 // to SNAKE_UPPER_CASE.
 function parseEnvConfig(env: Record<string, unknown>): Partial<UserConfig> {
+    const CONFIG_WITH_URLS: Set<string> = new Set<(typeof OPTIONS)["string"][number]>(["connectionString"]);
+
     function setValue(obj: Record<string, unknown>, path: string[], value: string): void {
         const currentField = path.shift();
         if (!currentField) {
             return;
         }
         if (path.length === 0) {
+            if (CONFIG_WITH_URLS.has(currentField)) {
+                obj[currentField] = value;
+                return;
+            }
+
             const numberValue = Number(value);
             if (!isNaN(numberValue)) {
                 obj[currentField] = numberValue;
@@ -249,7 +256,7 @@ function SNAKE_CASE_toCamelCase(str: string): string {
 // whatever is in mongosh.
 function parseCliConfig(args: string[]): CliOptions {
     const programArgs = args.slice(2);
-    const parsed = argv(programArgs, OPTIONS) as unknown as CliOptions &
+    const parsed = argv(programArgs, OPTIONS as unknown as argv.Options) as unknown as CliOptions &
         UserConfig & {
             _?: string[];
         };
diff --git a/tests/unit/common/config.test.ts b/tests/unit/common/config.test.ts
index a66c6e51..f325461d 100644
--- a/tests/unit/common/config.test.ts
+++ b/tests/unit/common/config.test.ts
@@ -12,6 +12,20 @@ import type { Secret } from "../../../src/common/keychain.js";
 
 describe("config", () => {
     describe("env var parsing", () => {
+        describe("mongodb urls", () => {
+            it("should not try to parse a multiple-host urls", () => {
+                const actual = setupUserConfig({
+                    env: {
+                        MDB_MCP_CONNECTION_STRING: "mongodb://user:password@host1,host2,host3/",
+                    },
+                    cli: [],
+                    defaults: defaultUserConfig,
+                });
+
+                expect(actual.connectionString).toEqual("mongodb://user:password@host1,host2,host3/");
+            });
+        });
+
         describe("string cases", () => {
             const testCases = [
                 { envVar: "MDB_MCP_API_BASE_URL", property: "apiBaseUrl", value: "http://test.com" },
@@ -67,6 +81,16 @@ describe("config", () => {
     });
 
     describe("cli parsing", () => {
+        it("should not try to parse a multiple-host urls", () => {
+            const actual = setupUserConfig({
+                cli: ["myself", "--", "--connectionString", "mongodb://user:password@host1,host2,host3/"],
+                env: {},
+                defaults: defaultUserConfig,
+            });
+
+            expect(actual.connectionString).toEqual("mongodb://user:password@host1,host2,host3/");
+        });
+
         describe("string use cases", () => {
             const testCases = [
                 {