diff --git a/backend/src/services/identity-aws-auth/identity-aws-auth-fns.ts b/backend/src/services/identity-aws-auth/identity-aws-auth-fns.ts
index d0fb4d323..c8b494e7b 100644
--- a/backend/src/services/identity-aws-auth/identity-aws-auth-fns.ts
+++ b/backend/src/services/identity-aws-auth/identity-aws-auth-fns.ts
@@ -2,7 +2,7 @@ interface PrincipalArnEntity {
   Partition: string;
   Service: "iam" | "sts";
   AccountNumber: string;
-  Type: "user" | "role" | "instance-profile";
+  Type: "user" | "role" | "instance-profile" | "assumed-role";
   Path: string;
   FriendlyName: string;
   SessionInfo: string; // Only populated for assumed-role
@@ -49,7 +49,7 @@ export const extractPrincipalArnEntity = (arn: string): PrincipalArnEntity => {
       }
       // assumed roles use a special format where the friendly name is the role name
       const [roleName, sessionId] = rest;
-      finalType = "role"; // treat assumed role case as role
+      finalType = "assumed-role";
       friendlyName = roleName;
       sessionInfo = sessionId;
       break;
@@ -87,5 +87,5 @@ export const extractPrincipalArnEntity = (arn: string): PrincipalArnEntity => {
 export const extractPrincipalArn = (arn: string) => {
   const entity = extractPrincipalArnEntity(arn);
 
-  return `arn:aws:iam::${entity.AccountNumber}:${entity.Type}/${entity.FriendlyName}`;
+  return `arn:aws:${entity.Service}::${entity.AccountNumber}:${entity.Type}/${entity.FriendlyName}`;
 };
diff --git a/backend/src/services/identity-aws-auth/identity-aws-auth-validators.ts b/backend/src/services/identity-aws-auth/identity-aws-auth-validators.ts
index 527d508f5..4e3884e15 100644
--- a/backend/src/services/identity-aws-auth/identity-aws-auth-validators.ts
+++ b/backend/src/services/identity-aws-auth/identity-aws-auth-validators.ts
@@ -6,7 +6,7 @@ const twelveDigitRegex = new RE2(/^\d{12}$/);
 // akhilmhdh: change this to a normal function later. Checked no redosable at the moment
 
 const arnRegex = new RE2(
-  /^arn:aws:iam::\d{12}:(user\/[a-zA-Z0-9_.@+*/-]+|role\/[a-zA-Z0-9_.@+*/-]+|assume-role\/[a-zA-Z0-9_.@+*/-]+|\*)$/
+  /^arn:aws:(iam|sts)::\d{12}:(user\/[a-zA-Z0-9_.@+*/-]+|role\/[a-zA-Z0-9_.@+*/-]+|assumed-role\/[a-zA-Z0-9_.@+*/-]+|\*)$/
 );
 
 export const validateAccountIds = z
@@ -55,7 +55,7 @@ export const validatePrincipalArns = z
     },
     {
       message:
-        "Each ARN must be in the format of 'arn:aws:iam::123456789012:user/UserName', 'arn:aws:iam::123456789012:role/RoleName', 'arn:aws:iam::123456789012:assume-role/RoleName', or 'arn:aws:iam::123456789012:*'."
+        "Each ARN must be in the format of 'arn:aws:iam::123456789012:user/UserName', 'arn:aws:iam::123456789012:role/RoleName', or 'arn:aws:iam::123456789012:*', 'arn:aws:sts::123456789012:assumed-role/RoleName'."
     }
   )
   // Transform to normalize the spaces around commas