diff --git a/src/lib.ts b/src/lib.ts
index 401e503..e7c5f46 100644
--- a/src/lib.ts
+++ b/src/lib.ts
@@ -23,11 +23,12 @@ export function normalizeDatabaseName(input: string) {
   return input
     .replace(/[\W_]+/g, '_')
     .substring(0, 64)
-    .replace(/^_|_$/g, '');
+    .replace(/^_|_$/g, '')
+    .toLowerCase();
 }
 
 export function normalizeDomainName(input: string) {
-  return input.replace(/\W+/g, '-').substring(0, 63).replace(/^-|-$/g, '');
+  return input.replace(/\W+/g, '-').substring(0, 63).replace(/^-|-$/g, '').toLowerCase();
 }
 
 export function updateDotEnvString(env: string, variables: Record<string, string | undefined>) {
diff --git a/tests/unit/lib.test.ts b/tests/unit/lib.test.ts
index 91b62d9..1c33989 100644
--- a/tests/unit/lib.test.ts
+++ b/tests/unit/lib.test.ts
@@ -59,6 +59,7 @@ describe('normalizeDatabaseName', () => {
     ['jbk/px-454', 'jbk_px_454'],
     ["please+don't %20 do / this", 'please_don_t_20_do_this'],
     ['a'.repeat(65), 'a'.repeat(64)],
+    ['FOO bar', 'foo_bar'],
   ])('%s → %s', (input, output) => {
     expect(normalizeDatabaseName(input)).toBe(output);
   });
@@ -74,6 +75,7 @@ describe('normalizeDomainName', () => {
     ['jbk/px-454', 'jbk-px-454'],
     ["please+don't %20 do / this", 'please-don-t-20-do-this'],
     ['a'.repeat(65), 'a'.repeat(63)],
+    ['FOO bar', 'foo-bar'],
   ])('%s → %s', (input, output) => {
     expect(normalizeDomainName(input)).toBe(output);
   });