diff --git a/app/test/testcoreutils.cpp b/app/test/testcoreutils.cpp
index 23d6d78e7..b4d8117b4 100644
--- a/app/test/testcoreutils.cpp
+++ b/app/test/testcoreutils.cpp
@@ -176,7 +176,7 @@ void TestCoreUtils::testNameValidation()
     { QStringLiteral( "-project" ), true },
     { QStringLiteral( "proj_ect" ), true },
     { QStringLiteral( "proj.ect" ), true },
-    { QStringLiteral( "proj!ect" ), true },
+    { QStringLiteral( "proj!ect" ), false },
 
     { QStringLiteral( " project" ), false },
     { QStringLiteral( ".project" ), false },
diff --git a/core/coreutils.cpp b/core/coreutils.cpp
index a17b38aa8..143e1f81b 100644
--- a/core/coreutils.cpp
+++ b/core/coreutils.cpp
@@ -271,9 +271,27 @@ bool CoreUtils::isAuthConfigFile( const QString filePath )
 
 bool CoreUtils::isValidName( const QString &name )
 {
-  static QRegularExpression reForbiddenmNames( R"([@#$%^&*\(\)\{\}\[\]\\\/\|\+=<>~\?:;,`\'\"]|^[\s^\.].*$|^CON$|^PRN$|^AUX$|^NUL$|^COM\d$|^LPT\d|^support$|^helpdesk$|^merginmaps$|^lutraconsulting$|^mergin$|^lutra$|^input$|^sales$|^admin$)", QRegularExpression::CaseInsensitiveOption );
-  QRegularExpressionMatch matchForbiddenNames = reForbiddenmNames.match( name );
-  return !matchForbiddenNames.hasMatch();
+  if ( name.length() > 255 )
+    return false;
+
+  // name must not start with whitespace, '^' or '.'
+  static QRegularExpression invalidFirstCharacterRe( R"(^[\s^\.].*$)", QRegularExpression::CaseInsensitiveOption );
+  if ( invalidFirstCharacterRe.match( name ).hasMatch() )
+    return false;
+
+  // name must not be a reserved Windows device filename (CON, PRN, AUX, NUL, COM1-9, LPT1-9)
+  static QRegularExpression invalidFilenameRe( R"(^CON$|^PRN$|^AUX$|^NUL$|^COM\d$|^LPT\d)", QRegularExpression::CaseInsensitiveOption );
+  if ( invalidFilenameRe.match( name ).hasMatch() )
+    return false;
+
+  // name must not be a word reserved by Mergin Maps / Lutra Consulting
+  static QRegularExpression reservedWordRe( R"(^support$|^helpdesk$|^merginmaps$|^lutraconsulting$|^mergin$|^lutra$|^input$|^sales$|^admin$)", QRegularExpression::CaseInsensitiveOption );
+  if ( reservedWordRe.match( name ).hasMatch() )
+    return false;
+
+  // name must contain only word characters, whitespace, '-' or '.'
+  static QRegularExpression validCharactersRe( R"(^[\w\s\-\.]+$)", QRegularExpression::UseUnicodePropertiesOption );
+  return validCharactersRe.match( name ).hasMatch();
 }
 
 QString CoreUtils::nameAbbr( const QString &name, const QString &email )