diff --git a/client/components/Search/Results/Graphical/ImageResultsList.test.tsx b/client/components/Search/Results/Graphical/ImageResultsList.test.tsx
index d0aabb31..6da75dfc 100644
--- a/client/components/Search/Results/Graphical/ImageResultsList.test.tsx
+++ b/client/components/Search/Results/Graphical/ImageResultsList.test.tsx
@@ -109,4 +109,60 @@ describe("ImageResultsList", () => {
     expect(slide).toBeInTheDocument();
     expect(slide?.getAttribute("style") ?? "").not.toContain("transition");
   });
+
+  it("opens the lightbox when a source URL is protocol-relative", async () => {
+    const user = userEvent.setup();
+    render(
+      <MantineProvider>
+        <ImageResultsList
+          imageResults={[
+            [
+              "Protocol-relative image",
+              "https://example.com/protocol-relative",
+              "https://example.com/protocol-relative.jpg",
+              "//cdn.example.com/protocol-relative.jpg",
+            ],
+          ]}
+        />
+      </MantineProvider>,
+    );
+
+    await user.click(
+      await screen.findByRole("button", {
+        name: "Open image preview: Protocol-relative image",
+      }),
+    );
+
+    const dialog = await screen.findByRole("dialog");
+    expect(dialog.textContent).toContain(
+      "Source: //cdn.example.com/protocol-relative.jpg",
+    );
+  });
+
+  it("opens the lightbox when a source URL is relative", async () => {
+    const user = userEvent.setup();
+    render(
+      <MantineProvider>
+        <ImageResultsList
+          imageResults={[
+            [
+              "Relative image",
+              "https://example.com/relative",
+              "https://example.com/relative.jpg",
+              "/images/relative.jpg",
+            ],
+          ]}
+        />
+      </MantineProvider>,
+    );
+
+    await user.click(
+      await screen.findByRole("button", {
+        name: "Open image preview: Relative image",
+      }),
+    );
+
+    const dialog = await screen.findByRole("dialog");
+    expect(dialog.textContent).toContain("Source: /images/relative.jpg");
+  });
 });
diff --git a/client/components/Search/Results/Graphical/ImageResultsList.tsx b/client/components/Search/Results/Graphical/ImageResultsList.tsx
index 39f66205..123c1a81 100644
--- a/client/components/Search/Results/Graphical/ImageResultsList.tsx
+++ b/client/components/Search/Results/Graphical/ImageResultsList.tsx
@@ -115,7 +115,7 @@ export default function ImageResultsList({
               )}
               {sourceUrl && (
                 <Text size="xs" c="dimmed">
-                  Source: {new URL(sourceUrl).hostname}
+                  Source: {getHostname(sourceUrl)}
                 </Text>
               )}
               <Group align="center" justify="center" gap="xs">