diff --git a/lib/fog/aws/credential_fetcher.rb b/lib/fog/aws/credential_fetcher.rb
index 0ce411419..7699b865d 100644
--- a/lib/fog/aws/credential_fetcher.rb
+++ b/lib/fog/aws/credential_fetcher.rb
@@ -44,7 +44,7 @@ module Fog
                 }
 
                 sts_endpoint =
-                  if ENV["AWS_STS_REGIONAL_ENDPOINTS"] == "regional"
+                  if ENV["AWS_STS_REGIONAL_ENDPOINTS"] == "regional" && region
                     "https://sts.#{region}.amazonaws.com"
                   else
                     "https://sts.amazonaws.com"
diff --git a/tests/credentials_tests.rb b/tests/credentials_tests.rb
index e3981769e..36f031e52 100644
--- a/tests/credentials_tests.rb
+++ b/tests/credentials_tests.rb
@@ -103,6 +103,17 @@ Shindo.tests('AWS | credentials', ['aws']) do
 
     ENV["AWS_STS_REGIONAL_ENDPOINTS"] = "regional"
 
+    tests('#fetch_credentials with no region specified') do
+      returns(
+        aws_access_key_id: 'dummykey',
+        aws_secret_access_key: 'dummysecret',
+        aws_session_token: 'dummytoken',
+        region: 'us-west-1',
+        sts_endpoint: "https://sts.amazonaws.com",
+        aws_credentials_expire_at: expires_at
+      ) { Fog::AWS::Compute.fetch_credentials(use_iam_profile: true) }
+    end
+
     tests('#fetch_credentials with regional STS endpoint') do
       returns(
         aws_access_key_id: 'dummykey',