diff --git a/lockfile/src/parsers/pypi.rs b/lockfile/src/parsers/pypi.rs
index 8eb996a05..e2330f816 100644
--- a/lockfile/src/parsers/pypi.rs
+++ b/lockfile/src/parsers/pypi.rs
@@ -57,7 +57,9 @@ fn line<'a>(input: &'a str, registry: &mut Option<&'a str>) -> IResult<&'a str,
     //
     // Since `ThirdPartyVersion` only allows a single registry, we only record the
     // primary one.
-    if let Some(index_url) = line.strip_prefix("--index-url") {
+    if let Some(index_url) =
+        line.strip_prefix("--index-url ").or_else(|| line.strip_prefix("-i "))
+    {
         *registry = Some(index_url.trim());
         line = "";
     }
diff --git a/lockfile/src/python.rs b/lockfile/src/python.rs
index f383c3b87..ea55da30f 100644
--- a/lockfile/src/python.rs
+++ b/lockfile/src/python.rs
@@ -304,7 +304,7 @@ mod tests {
             Package {
                 name: "other-registry".into(),
                 version: PackageVersion::ThirdParty(ThirdPartyVersion {
-                    registry: "https://mirror1.phylum.io/simple/".into(),
+                    registry: "https://mirror2.phylum.io/simple/".into(),
                     version: "1.2.3".into(),
                 }),
                 package_type: PackageType::PyPi,
diff --git a/tests/fixtures/requirements-locked.txt b/tests/fixtures/requirements-locked.txt
index c59235206..c1515d4ee 100644
--- a/tests/fixtures/requirements-locked.txt
+++ b/tests/fixtures/requirements-locked.txt
@@ -34,5 +34,6 @@ tomli @ https://files.pythonhosted.org/packages/97/75/10a9ebee3fd790d20926a90a25
 -e /tmp/editable ; python_version >= "3.7" and python_version < "3.12"
 
 --index-url https://mirror1.phylum.io/simple/
---extra-index-url https://mirror2.phylum.io/simple/
+-i https://mirror2.phylum.io/simple/
+--extra-index-url https://mirror3.phylum.io/simple/
 other-registry==1.2.3