diff --git a/Pipfile b/Pipfile
index d80ff30..70f3124 100644
--- a/Pipfile
+++ b/Pipfile
@@ -6,7 +6,7 @@ verify_ssl = true
 [packages]
 flask = "~=2.3.0"
 requests = "~=2.32.3"
-jira = "~=3.0.0"
+jira = "~=3.10.0"
 logging-formatter-anticrlf = "~=1.2.1"
 
 [dev-packages]
diff --git a/action.yml b/action.yml
index 544f767..7a04a62 100644
--- a/action.yml
+++ b/action.yml
@@ -35,6 +35,10 @@ inputs:
     description: 'Custom reopen state'
     required: false
     default: 'To Do'
+  jira_api_version:
+    description: 'Jira REST API version. Use "3" for Jira Cloud (default), "2" for Jira Server/Data Center.'
+    required: false
+    default: '3'
 runs:
   using: composite
   steps:
@@ -51,6 +55,7 @@ runs:
       INPUTS_SYNC_DIRECTION: ${{ inputs.sync_direction }}
       INPUTS_ISSUE_END_STATE: ${{ inputs.issue_end_state }}
       INPUTS_ISSUE_REOPEN_STATE: ${{ inputs.issue_reopen_state }}
+      INPUTS_JIRA_API_VERSION: ${{ inputs.jira_api_version }}
     run: |
       pip3 install pipenv
       pipenv install
@@ -68,4 +73,5 @@ runs:
         --jira-labels "$INPUTS_JIRA_LABELS" \
         --direction "$INPUTS_SYNC_DIRECTION" \
         --issue-end-state "$INPUTS_ISSUE_END_STATE" \
-        --issue-reopen-state "$INPUTS_ISSUE_REOPEN_STATE"
+        --issue-reopen-state "$INPUTS_ISSUE_REOPEN_STATE" \
+        --jira-api-version "$INPUTS_JIRA_API_VERSION"
diff --git a/cli.py b/cli.py
index c2aa558..8099aac 100644
--- a/cli.py
+++ b/cli.py
@@ -52,7 +52,7 @@ def serve(args):
         fail("No Webhook secret specified!")
 
     github = ghlib.GitHub(args.gh_url, args.gh_token)
-    jira = jiralib.Jira(args.jira_url, args.jira_user, args.jira_token)
+    jira = jiralib.Jira(args.jira_url, args.jira_user, args.jira_token, args.jira_api_version)
     s = Sync(
         github,
         jira.getProject(args.jira_project, args.jira_labels),
@@ -81,7 +81,7 @@ def sync(args):
         fail("No GitHub repository specified!")
 
     github = ghlib.GitHub(args.gh_url, args.gh_token)
-    jira = jiralib.Jira(args.jira_url, args.jira_user, args.jira_token)
+    jira = jiralib.Jira(args.jira_url, args.jira_user, args.jira_token, args.jira_api_version)
     jira_project = jira.getProject(
         args.jira_project,
         args.issue_end_state,
@@ -143,7 +143,7 @@ def install_hooks(args):
     if args.jira_url:
         if not args.jira_user or not args.jira_token:
             fail("No JIRA credentials specified!")
-        jira = jiralib.Jira(args.jira_url, args.jira_user, args.jira_token)
+        jira = jiralib.Jira(args.jira_url, args.jira_user, args.jira_token, args.jira_api_version)
         jira.create_hook("github_jira_synchronization_hook", args.hook_url, args.secret)
 
 
@@ -175,7 +175,7 @@ def list_hooks(args):
         if not args.jira_user or not args.jira_token:
             fail("No JIRA credentials specified!")
 
-        jira = jiralib.Jira(args.jira_url, args.jira_user, args.jira_token)
+        jira = jiralib.Jira(args.jira_url, args.jira_user, args.jira_token, args.jira_api_version)
 
         for h in jira.list_hooks():
             print(json.dumps(h, indent=4))
@@ -203,6 +203,11 @@ def main():
     )
     credential_base.add_argument("--jira-project", help="JIRA project key")
     credential_base.add_argument("--jira-labels", help="JIRA bug label(s)")
+    credential_base.add_argument(
+        "--jira-api-version",
+        help="JIRA REST API version (default: 3). Use '2' for Jira Server/Data Center.",
+        default=os.getenv("GH2JIRA_JIRA_API_VERSION", "3"),
+    )
     credential_base.add_argument(
         "--secret",
         help="Webhook secret. Alternatively, the GH2JIRA_SECRET may be set.",
diff --git a/jiralib.py b/jiralib.py
index a6bf0e9..2790f83 100644
--- a/jiralib.py
+++ b/jiralib.py
@@ -46,11 +46,11 @@
 
 
 class Jira:
-    def __init__(self, url, user, token):
+    def __init__(self, url, user, token, api_version="3"):
         self.url = url
         self.user = user
         self.token = token
-        self.j = JIRA(url, basic_auth=(user, token))
+        self.j = JIRA(url, basic_auth=(user, token), options={"rest_api_version": api_version})
 
     def auth(self):
         return self.user, self.token
@@ -119,7 +119,7 @@ def get_state_issue(self, issue_key="-"):
         issues = list(
             filter(
                 lambda i: i.fields.summary == STATE_ISSUE_SUMMARY,
-                self.j.search_issues(issue_search, maxResults=0),
+                self.j.enhanced_search_issues(issue_search, maxResults=0),
             )
         )
 
@@ -218,7 +218,7 @@ def fetch_issues(self, key):
                 lambda i: i.is_managed(),
                 [
                     JiraIssue(self, raw)
-                    for raw in self.j.search_issues(issue_search, maxResults=0)
+                    for raw in self.j.enhanced_search_issues(issue_search, maxResults=0)
                 ],
             )
         )