diff --git a/.changeset/neat-cooks-sell.md b/.changeset/neat-cooks-sell.md
new file mode 100644
index 0000000000..11859c3589
--- /dev/null
+++ b/.changeset/neat-cooks-sell.md
@@ -0,0 +1,5 @@
+---
+'@backstage/core-components': patch
+---
+
+Fix search in Firefox. When the search was performed by pressing enter, the query parameter was first set but then reverted back.
diff --git a/packages/core-components/src/layout/Sidebar/Items.tsx b/packages/core-components/src/layout/Sidebar/Items.tsx
index fbe1ffbb82..1246fda82e 100644
--- a/packages/core-components/src/layout/Sidebar/Items.tsx
+++ b/packages/core-components/src/layout/Sidebar/Items.tsx
@@ -311,6 +311,7 @@ export function SidebarSearchField(props: SidebarSearchFieldProps) {
   const handleEnter: KeyboardEventHandler = ev => {
     if (ev.key === 'Enter') {
       search();
+      ev.preventDefault();
     }
   };