diff --git a/CHANGELOG.md b/CHANGELOG.md
index c11bd126..0ab02d05 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Fixed
+
+- Fix helm env variable validation logic when specifying Twilio auth related values by @njohnstone2 ([#2674](https://github.com/grafana/oncall/pull/2674))
+
 ## v1.3.19 (2023-07-28)
 
 ### Fixed
diff --git a/helm/oncall/templates/_env.tpl b/helm/oncall/templates/_env.tpl
index 3632789e..6ee7207a 100644
--- a/helm/oncall/templates/_env.tpl
+++ b/helm/oncall/templates/_env.tpl
@@ -121,11 +121,13 @@
     secretKeyRef:
       name: {{ .existingSecret }}
       key: {{ required "oncall.twilio.accountSid is required if oncall.twilio.existingSecret is not empty" .accountSid | quote }}
+{{- if .authTokenKey }}
 - name: TWILIO_AUTH_TOKEN
   valueFrom:
     secretKeyRef:
       name: {{ .existingSecret }}
       key: {{ required "oncall.twilio.authTokenKey is required if oncall.twilio.existingSecret is not empty" .authTokenKey | quote }}
+{{- end }}
 - name: TWILIO_NUMBER
   valueFrom:
     secretKeyRef:
@@ -136,6 +138,7 @@
     secretKeyRef:
       name: {{ .existingSecret }}
       key: {{ required "oncall.twilio.verifySidKey is required if oncall.twilio.existingSecret is not empty" .verifySidKey | quote }}
+{{- if and .apiKeySidKey .apiKeySecretKey }}
 - name: TWILIO_API_KEY_SID
   valueFrom:
     secretKeyRef:
@@ -146,6 +149,7 @@
     secretKeyRef:
       name: {{ .existingSecret }}
       key: {{ required "oncall.twilio.apiKeySecretKey is required if oncall.twilio.existingSecret is not empty" .apiKeySecretKey | quote }}
+{{- end }}
 {{- else }}
 {{- if .accountSid }}
 - name: TWILIO_ACCOUNT_SID
diff --git a/helm/oncall/tests/twilio_auth_env_test.yaml b/helm/oncall/tests/twilio_auth_env_test.yaml
new file mode 100644
index 00000000..01ee8be7
--- /dev/null
+++ b/helm/oncall/tests/twilio_auth_env_test.yaml
@@ -0,0 +1,48 @@
+suite: test Twilio auth envs for deployments
+release:
+  name: oncall
+templates:
+  - engine/deployment.yaml
+tests:
+  - it: snippet.oncall.twilio.env -> should succeed if only apiKeySid and apiKeySecret are set
+    set:
+      oncall.twilio.existingSecret: unittest-secret
+      oncall.twilio.accountSid: "acc-sid"
+      oncall.twilio.phoneNumberKey: "phone-key"
+      oncall.twilio.verifySidKey: "verify-sid-key"
+      oncall.twilio.apiKeySidKey: "api-sid-key"
+      oncall.twilio.apiKeySecretKey: "api-secret-key"
+    asserts:
+      - contains:
+          path: spec.template.spec.containers[0].env
+          content:
+            name: TWILIO_API_KEY_SID
+            valueFrom:
+              secretKeyRef:
+                key: api-sid-key
+                name: unittest-secret
+      - contains:
+          path: spec.template.spec.containers[0].env
+          content:
+            name: TWILIO_API_KEY_SECRET
+            valueFrom:
+              secretKeyRef:
+                key: api-secret-key
+                name: unittest-secret
+
+  - it: snippet.oncall.twilio.env -> should succeed if only authToken is set
+    set:
+      oncall.twilio.existingSecret: unittest-secret
+      oncall.twilio.accountSid: "acc-sid"
+      oncall.twilio.verifySidKey: "verify-sid-key"
+      oncall.twilio.phoneNumberKey: "phone-key"
+      oncall.twilio.authTokenKey: "auth-token-key"
+    asserts:
+      - contains:
+          path: spec.template.spec.containers[0].env
+          content:
+            name: TWILIO_AUTH_TOKEN
+            valueFrom:
+              secretKeyRef:
+                key: auth-token-key
+                name: unittest-secret