diff --git a/libraries/core/src/main/kotlin/io/element/android/libraries/core/uri/UrlUtils.kt b/libraries/core/src/main/kotlin/io/element/android/libraries/core/uri/UrlUtils.kt
index 666ee1d7ab..91402e3d11 100644
--- a/libraries/core/src/main/kotlin/io/element/android/libraries/core/uri/UrlUtils.kt
+++ b/libraries/core/src/main/kotlin/io/element/android/libraries/core/uri/UrlUtils.kt
@@ -20,12 +20,13 @@ fun String.isValidUrl(): Boolean {
 }
 
 /**
- * Ensure string starts with "http". If it is not the case, "https://" is added, only if the String is not empty
+ * Ensure string starts with "http" (case-insensitively, so "HTTP://" / "HTTPS://" are respected). If it is
+ * not the case, "https://" is added, only if the String is not empty.
  */
 fun String.ensureProtocol(): String {
     return when {
         isEmpty() -> this
-        !startsWith("http") -> "https://$this"
+        !startsWith("http", ignoreCase = true) -> "https://$this"
         else -> this
     }
 }
diff --git a/libraries/core/src/test/kotlin/io/element/android/libraries/core/uri/UrlUtilsTest.kt b/libraries/core/src/test/kotlin/io/element/android/libraries/core/uri/UrlUtilsTest.kt
new file mode 100644
index 0000000000..9a9d68dcaa
--- /dev/null
+++ b/libraries/core/src/test/kotlin/io/element/android/libraries/core/uri/UrlUtilsTest.kt
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.core.uri
+
+import com.google.common.truth.Truth.assertThat
+import org.junit.Test
+
+class UrlUtilsTest {
+    @Test
+    fun `ensureProtocol keeps an empty string unchanged`() {
+        assertThat("".ensureProtocol()).isEqualTo("")
+    }
+
+    @Test
+    fun `ensureProtocol prepends https when there is no scheme`() {
+        assertThat("matrix.org".ensureProtocol()).isEqualTo("https://matrix.org")
+    }
+
+    @Test
+    fun `ensureProtocol keeps an existing http or https scheme`() {
+        assertThat("https://matrix.org".ensureProtocol()).isEqualTo("https://matrix.org")
+        assertThat("http://matrix.org".ensureProtocol()).isEqualTo("http://matrix.org")
+    }
+
+    @Test
+    fun `ensureProtocol keeps an uppercase scheme rather than double-prepending`() {
+        assertThat("HTTPS://matrix.org".ensureProtocol()).isEqualTo("HTTPS://matrix.org")
+        assertThat("Http://matrix.org".ensureProtocol()).isEqualTo("Http://matrix.org")
+    }
+}