diff --git a/changelogs/fragments/783-fix-gem-installed-versions.yaml b/changelogs/fragments/783-fix-gem-installed-versions.yaml
new file mode 100644
index 0000000000..5ad70f8295
--- /dev/null
+++ b/changelogs/fragments/783-fix-gem-installed-versions.yaml
@@ -0,0 +1,2 @@
+bugfixes:
+  - "gem - fix get_installed_versions: correctly parse ``default`` version (https://github.com/ansible-collections/community.general/pull/783)."
diff --git a/plugins/modules/packaging/language/gem.py b/plugins/modules/packaging/language/gem.py
index f686f74924..3d24039f9b 100644
--- a/plugins/modules/packaging/language/gem.py
+++ b/plugins/modules/packaging/language/gem.py
@@ -157,7 +157,7 @@ def get_installed_versions(module, remote=False):
     (rc, out, err) = module.run_command(cmd, environ_update=environ, check_rc=True)
     installed_versions = []
     for line in out.splitlines():
-        match = re.match(r"\S+\s+\((.+)\)", line)
+        match = re.match(r"\S+\s+\((?:default: )?(.+)\)", line)
         if match:
             versions = match.group(1)
             for version in versions.split(', '):