diff --git a/changelogs/fragments/5687-gconftool2.yml b/changelogs/fragments/5687-gconftool2.yml
new file mode 100644
index 0000000000..4a35131efa
--- /dev/null
+++ b/changelogs/fragments/5687-gconftool2.yml
@@ -0,0 +1,2 @@
+bugfixes:
+  - "gconftool2 - fix crash that prevents setting a key (https://github.com/ansible-collections/community.general/issues/5591, https://github.com/ansible-collections/community.general/pull/5687)."
diff --git a/plugins/modules/system/gconftool2.py b/plugins/modules/system/gconftool2.py
index 7ade53e3f4..f50abc76ee 100644
--- a/plugins/modules/system/gconftool2.py
+++ b/plugins/modules/system/gconftool2.py
@@ -125,7 +125,7 @@ class GConf2Preference(object):
             elif call_type == 'set':
                 cmd.extend(direct)
                 cmd.extend(config_source)
-                cmd.extend(["--type", self.value_type, "--{3}".format(call_type), self.key, self.value])
+                cmd.extend(["--type", self.value_type, "--{0}".format(call_type), self.key, self.value])
             elif call_type == 'unset':
                 cmd.extend(["--unset", self.key])