diff --git a/oauth/src/OAuthClient.kt b/oauth/src/OAuthClient.kt
index 424a3b9e..d82e1291 100644
--- a/oauth/src/OAuthClient.kt
+++ b/oauth/src/OAuthClient.kt
@@ -67,7 +67,7 @@ class GoogleOAuthClient(httpClient: HttpClient): OAuthClient(
     val res = fetchProfileResponse(token)
     val email = Email(res.getString("email"))
     return UserProfile(provider, res.getString("id"), email,
-      res.getOrNull("givenName") ?: email.value.substringBefore("@").capitalize(), res.getOrNull("familyName") ?: "",
+      res.getOrNull("givenName") ?: email.extractName(), res.getOrNull("familyName") ?: "",
       res.getOrNull<String>("picture")?.let { URI(it) }, res.getLocale())
   }
 }
@@ -82,8 +82,8 @@ class MicrosoftOAuthClient(httpClient: HttpClient): OAuthClient(
 ) {
   override suspend fun profile(token: OAuthTokenResponse, exchange: HttpExchange): UserProfile {
     val res = fetchProfileResponse(token)
-    val email = res.getOrNull("mail") ?: res.getOrNull<String>("userPrincipalName") ?: error("Cannot obtain user's email")
-    return UserProfile(provider, res.getString("id"), Email(email), res.getOrNull("givenName") ?: email.substringBefore("@").capitalize(), res.getOrNull("surname") ?: "",
+    val email = Email(res.getOrNull("mail") ?: res.getOrNull<String>("userPrincipalName") ?: error("Cannot obtain user's email"))
+    return UserProfile(provider, res.getString("id"), email, res.getOrNull("givenName") ?: email.extractName(), res.getOrNull("surname") ?: "",
       locale = res.getLocale("preferredLanguage"))
   }
 }
@@ -102,7 +102,7 @@ class FacebookOAuthClient(httpClient: HttpClient): OAuthClient(
     val avatarExists = avatarData?.getOrNull<Boolean>("is_silhouette") != true
     val email = Email(res.getString("email"))
     return UserProfile(provider, res.getString("id"),
-      email, res.getOrNull("firstName") ?: email.value.substringBefore("@").capitalize(), res.getOrNull("lastName") ?: "",
+      email, res.getOrNull("firstName") ?: email.extractName(), res.getOrNull("lastName") ?: "",
       avatarData?.getOrNull<String>("url")?.takeIf { avatarExists }?.let { URI(it) },
       res.getLocale())
   }
@@ -119,7 +119,7 @@ class AppleOAuthClient(httpClient: HttpClient): OAuthClient(
   override suspend fun profile(token: OAuthTokenResponse, exchange: HttpExchange): UserProfile {
     val email = token.idToken!!.payload.email!!
     val user = exchange.bodyParams["user"]?.let { http.json.parse<AppleUserProfile>(it.toString()) }
-    return UserProfile(provider, token.idToken.payload.subject, email, user?.name?.firstName ?: email.value.substringBefore("@").capitalize(), user?.name?.lastName ?: "")
+    return UserProfile(provider, token.idToken.payload.subject, email, user?.name?.firstName ?: email.extractName(), user?.name?.lastName ?: "")
   }
 
   data class AppleUserProfile(val name: AppleUserName, val email: Email)
@@ -128,3 +128,10 @@ class AppleOAuthClient(httpClient: HttpClient): OAuthClient(
 
 data class OAuthTokenResponse(val accessToken: String, val expiresIn: Int, val scope: String? = null, val tokenType: String? = null, val idToken: JWT? = null, val refreshToken: String? = null)
 data class UserProfile(val provider: String, override val id: String, override val email: Email, override val firstName: String, override val lastName: String, val avatarUrl: URI? = null, val locale: Locale? = null): OAuthUser
+
+internal fun Email.extractName(): String {
+  val localPart = value.substringBefore("@")
+  return localPart.replaceFirstChar {
+    if (it.isLowerCase()) it.titlecase(Locale.getDefault()) else it.toString()
+  }
+}
diff --git a/oauth/test/OAuthClientKtTest.kt b/oauth/test/OAuthClientKtTest.kt
new file mode 100644
index 00000000..6c854b38
--- /dev/null
+++ b/oauth/test/OAuthClientKtTest.kt
@@ -0,0 +1,32 @@
+import ch.tutteli.atrium.api.fluent.en_GB.toEqual
+import ch.tutteli.atrium.api.verbs.expect
+import klite.Email
+import klite.oauth.extractName
+import org.junit.jupiter.params.ParameterizedTest
+import org.junit.jupiter.params.provider.Arguments
+import org.junit.jupiter.params.provider.MethodSource
+import java.util.stream.Stream
+
+class OAuthClientKtTest {
+
+  @ParameterizedTest
+  @MethodSource("emailTestCases")
+  fun `use capitalized email local part as name`(emailAddress: String, expectedName: String) {
+    val email = Email(emailAddress)
+    expect(email.extractName()).toEqual(expectedName)
+  }
+
+  companion object {
+    @JvmStatic
+    fun emailTestCases(): Stream<Arguments> =
+      Stream.of(
+        Arguments.of("foo@bar.com", "Foo"),
+        Arguments.of("fOo@bar.com", "Foo"),
+        Arguments.of("john.doe@example.com", "John.doe"),
+        Arguments.of("alice@example.org", "Alice"),
+        Arguments.of("bob-smith@mail.co.uk", "Bob-smith"),
+        Arguments.of("1234@numeric.com", "1234"),
+        Arguments.of("UPPERCASE@example.com", "Uppercase")
+      )
+  }
+}