diff --git a/jenkins_jobs/modules/triggers.py b/jenkins_jobs/modules/triggers.py
index 56485ebd6..3f75ad477 100644
--- a/jenkins_jobs/modules/triggers.py
+++ b/jenkins_jobs/modules/triggers.py
@@ -1117,7 +1117,10 @@ def github_pull_request(registry, xml_parent, data):
         error_comment
     )
 
-    cancel_builds_on_update = data.get('cancel-builds-on-update', False)
+    # When the value of cancel-builds-on-update comes from deep_formatter,
+    # the value is of type 'str', otherwise the value is of type 'bool'
+    cancel_builds_on_update = str(
+        data.get('cancel-builds-on-update', False)).lower() == 'true'
 
     # We want to have only one 'extensions' subelement, even if status
     # handling, comment handling and other extensions are enabled.
diff --git a/tests/yamlparser/fixtures/github_cancel_builds_on_update_variable001.xml b/tests/yamlparser/fixtures/github_cancel_builds_on_update_variable001.xml
new file mode 100644
index 000000000..0832d9602
--- /dev/null
+++ b/tests/yamlparser/fixtures/github_cancel_builds_on_update_variable001.xml
@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="utf-8"?>
+<project>
+  <actions/>
+  <description>&lt;!-- Managed by Jenkins Job Builder --&gt;</description>
+  <keepDependencies>false</keepDependencies>
+  <blockBuildWhenDownstreamBuilding>false</blockBuildWhenDownstreamBuilding>
+  <blockBuildWhenUpstreamBuilding>false</blockBuildWhenUpstreamBuilding>
+  <concurrentBuild>false</concurrentBuild>
+  <canRoam>true</canRoam>
+  <properties/>
+  <scm class="hudson.scm.NullSCM"/>
+  <triggers class="vector">
+    <org.jenkinsci.plugins.ghprb.GhprbTrigger>
+      <adminlist/>
+      <whitelist/>
+      <orgslist/>
+      <whiteListLabels/>
+      <blackListLabels/>
+      <excludedRegions/>
+      <includedRegions/>
+      <spec/>
+      <allowMembersOfWhitelistedOrgsAsAdmin>false</allowMembersOfWhitelistedOrgsAsAdmin>
+      <cron/>
+      <triggerPhrase/>
+      <skipBuildPhrase/>
+      <onlyTriggerPhrase>false</onlyTriggerPhrase>
+      <useGitHubHooks>false</useGitHubHooks>
+      <permitAll>false</permitAll>
+      <autoCloseFailedPullRequests>false</autoCloseFailedPullRequests>
+      <extensions>
+        <org.jenkinsci.plugins.ghprb.extensions.build.GhprbCancelBuildsOnUpdate/>
+      </extensions>
+    </org.jenkinsci.plugins.ghprb.GhprbTrigger>
+  </triggers>
+  <builders/>
+  <publishers/>
+  <buildWrappers/>
+</project>
diff --git a/tests/yamlparser/fixtures/github_cancel_builds_on_update_variable001.yaml b/tests/yamlparser/fixtures/github_cancel_builds_on_update_variable001.yaml
new file mode 100644
index 000000000..a3245c2c2
--- /dev/null
+++ b/tests/yamlparser/fixtures/github_cancel_builds_on_update_variable001.yaml
@@ -0,0 +1,12 @@
+---
+- job-template:
+    name: 'github-pull-request-variable-test-true'
+    triggers:
+      - github-pull-request:
+          cancel-builds-on-update: '{test-var}'
+
+- project:
+    name: test-true
+    test-var: true
+    jobs:
+      - 'github-pull-request-variable-test-true'
diff --git a/tests/yamlparser/fixtures/github_cancel_builds_on_update_variable002.xml b/tests/yamlparser/fixtures/github_cancel_builds_on_update_variable002.xml
new file mode 100644
index 000000000..1d9133094
--- /dev/null
+++ b/tests/yamlparser/fixtures/github_cancel_builds_on_update_variable002.xml
@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="utf-8"?>
+<project>
+  <actions/>
+  <description>&lt;!-- Managed by Jenkins Job Builder --&gt;</description>
+  <keepDependencies>false</keepDependencies>
+  <blockBuildWhenDownstreamBuilding>false</blockBuildWhenDownstreamBuilding>
+  <blockBuildWhenUpstreamBuilding>false</blockBuildWhenUpstreamBuilding>
+  <concurrentBuild>false</concurrentBuild>
+  <canRoam>true</canRoam>
+  <properties/>
+  <scm class="hudson.scm.NullSCM"/>
+  <triggers class="vector">
+    <org.jenkinsci.plugins.ghprb.GhprbTrigger>
+      <adminlist/>
+      <whitelist/>
+      <orgslist/>
+      <whiteListLabels/>
+      <blackListLabels/>
+      <excludedRegions/>
+      <includedRegions/>
+      <spec/>
+      <allowMembersOfWhitelistedOrgsAsAdmin>false</allowMembersOfWhitelistedOrgsAsAdmin>
+      <cron/>
+      <triggerPhrase/>
+      <skipBuildPhrase/>
+      <onlyTriggerPhrase>false</onlyTriggerPhrase>
+      <useGitHubHooks>false</useGitHubHooks>
+      <permitAll>false</permitAll>
+      <autoCloseFailedPullRequests>false</autoCloseFailedPullRequests>
+    </org.jenkinsci.plugins.ghprb.GhprbTrigger>
+  </triggers>
+  <builders/>
+  <publishers/>
+  <buildWrappers/>
+</project>
diff --git a/tests/yamlparser/fixtures/github_cancel_builds_on_update_variable002.yaml b/tests/yamlparser/fixtures/github_cancel_builds_on_update_variable002.yaml
new file mode 100644
index 000000000..39c35c423
--- /dev/null
+++ b/tests/yamlparser/fixtures/github_cancel_builds_on_update_variable002.yaml
@@ -0,0 +1,12 @@
+---
+- job-template:
+    name: 'github-pull-request-variable-test-false'
+    triggers:
+      - github-pull-request:
+          cancel-builds-on-update: '{test-var}'
+
+- project:
+    name: test-false
+    test-var: false
+    jobs:
+      - 'github-pull-request-variable-test-false'