diff --git a/src/Secrets.php b/src/Secrets.php
index 639e815..de6a349 100644
--- a/src/Secrets.php
+++ b/src/Secrets.php
@@ -42,8 +42,9 @@ public static function loadSecretEnvironmentVariables(?SsmClient $ssmClient = nu
             return self::retrieveParametersFromSsm($ssmClient, array_values($ssmNames));
         });
 
-        foreach ($parameters as $parameterName => $parameterValue) {
-            $envVar = array_search($parameterName, $ssmNames, true);
+        foreach ($envVarsToDecrypt as $envVar => $prefixedSsmRefName) {
+            $parameterName = substr($prefixedSsmRefName, strlen('bref-ssm:'));
+            $parameterValue = $parameters[$parameterName];
             $_SERVER[$envVar] = $_ENV[$envVar] = $parameterValue;
             putenv("$envVar=$parameterValue");
         }
diff --git a/tests/SecretsTest.php b/tests/SecretsTest.php
index 6792ace..9c85a10 100644
--- a/tests/SecretsTest.php
+++ b/tests/SecretsTest.php
@@ -11,6 +11,11 @@
 
 class SecretsTest extends TestCase
 {
+    private array $resultParams = [
+        'Name' => '/some/parameter',
+        'Value' => 'foobar',
+    ];
+
     public function setUp(): void
     {
         if (file_exists(sys_get_temp_dir() . '/bref-ssm-parameters.php')) {
@@ -27,13 +32,18 @@ public function test decrypts env variables(): void
         $this->assertSame('bref-ssm:/some/parameter', getenv('SOME_VARIABLE'));
         $this->assertSame('helloworld', getenv('SOME_OTHER_VARIABLE'));
 
-        Secrets::loadSecretEnvironmentVariables($this->mockSsmClient());
+        $ssmClient = $this->mockSsmClient([new Parameter($this->resultParams)]);
+        Secrets::loadSecretEnvironmentVariables($ssmClient);
 
         $this->assertSame('foobar', getenv('SOME_VARIABLE'));
         $this->assertSame('foobar', $_SERVER['SOME_VARIABLE']);
         $this->assertSame('foobar', $_ENV['SOME_VARIABLE']);
         // Check that the other variable was not modified
         $this->assertSame('helloworld', getenv('SOME_OTHER_VARIABLE'));
+
+        // Cleanup
+        putenv('SOME_VARIABLE');
+        putenv('SOME_OTHER_VARIABLE');
     }
 
     public function test caches parameters to call SSM only once(): void
@@ -41,11 +51,37 @@ public function test caches parameters to call SSM only once(): void
         putenv('SOME_VARIABLE=bref-ssm:/some/parameter');
 
         // Call twice, the mock will assert that SSM was only called once
-        $ssmClient = $this->mockSsmClient();
+        $ssmClient = $this->mockSsmClient([new Parameter($this->resultParams)]);
         Secrets::loadSecretEnvironmentVariables($ssmClient);
         Secrets::loadSecretEnvironmentVariables($ssmClient);
 
         $this->assertSame('foobar', getenv('SOME_VARIABLE'));
+
+        // Cleanup
+        putenv('SOME_VARIABLE');
+    }
+
+    public function test same ssm value can be assigned more than once(): void
+    {
+        putenv('VAR1=bref-ssm:/some/parameter');
+        putenv('VAR2=bref-ssm:/some/parameter');
+
+        // Sanity checks
+        $this->assertSame('bref-ssm:/some/parameter', getenv('VAR1'));
+        $this->assertSame('bref-ssm:/some/parameter', getenv('VAR2'));
+
+        $ssmClient = $this->mockSsmClient([
+            new Parameter($this->resultParams),
+            new Parameter($this->resultParams),
+        ]);
+        Secrets::loadSecretEnvironmentVariables($ssmClient);
+
+        $this->assertSame('foobar', getenv('VAR1'));
+        $this->assertSame('foobar', getenv('VAR2'));
+
+        // Cleanup
+        putenv('VAR1');
+        putenv('VAR2');
     }
 
     public function test throws a clear error message on missing permissions(): void
@@ -62,9 +98,15 @@ public function test throws a clear error message on missing permissions
         $expected = preg_quote("Bref was not able to resolve secrets contained in environment variables from SSM because of a permissions issue with the SSM API. Did you add IAM permissions in serverless.yml to allow Lambda to access SSM? (docs: https://bref.sh/docs/environment/variables.html#at-deployment-time).\nFull exception message:", '/');
         $this->expectExceptionMessageMatches("/$expected .+/");
         Secrets::loadSecretEnvironmentVariables($ssmClient);
+
+        // Cleanup
+        putenv('SOME_VARIABLE');
     }
 
-    private function mockSsmClient(): SsmClient
+    /**
+     * @param array<Parameter> $resultParameters
+     */
+    private function mockSsmClient(array $resultParameters): SsmClient
     {
         $ssmClient = $this->getMockBuilder(SsmClient::class)
             ->disableOriginalConstructor()
@@ -72,18 +114,17 @@ private function mockSsmClient(): SsmClient
             ->getMock();
 
         $result = ResultMockFactory::create(GetParametersResult::class, [
-            'Parameters' => [
-                new Parameter([
-                    'Name' => '/some/parameter',
-                    'Value' => 'foobar',
-                ]),
-            ],
+            'Parameters' => $resultParameters,
         ]);
 
+        $expectedNames = [];
+        foreach ($resultParameters as $resultParameter) {
+            $expectedNames[] = $resultParameter->getName();
+        }
         $ssmClient->expects($this->once())
             ->method('getParameters')
             ->with([
-                'Names' => ['/some/parameter'],
+                'Names' => $expectedNames,
                 'WithDecryption' => true,
             ])
             ->willReturn($result);