diff --git a/ets2panda/es2panda.h b/ets2panda/es2panda.h
index b7e93a6cbdfdccd79d8f1575898297d78211e8cb..9b69010cf70ee3cf64fbcd98691dd9722f2d18d7 100644
--- a/ets2panda/es2panda.h
+++ b/ets2panda/es2panda.h
@@ -94,6 +94,7 @@ struct SourceFile {
     bool isModule {};
     // NOTE(dkofanov): Should be aligned with 'Program::moduleInfo_'.
     bool isDeclForDynamicStaticInterop {};
+    bool isExternalSourceImport {};
     std::string_view dest {};
     // NOLINTEND(misc-non-private-member-variables-in-classes)
 };
diff --git a/ets2panda/lexer/ETSLexer.cpp b/ets2panda/lexer/ETSLexer.cpp
index 09ebb112982d974fccde8a068a795a75092bab36..bc0330997c2783c43c23cc60011ef620b055369e 100644
--- a/ets2panda/lexer/ETSLexer.cpp
+++ b/ets2panda/lexer/ETSLexer.cpp
@@ -20,6 +20,7 @@ namespace ark::es2panda::lexer {
 // NOLINTNEXTLINE(google-default-arguments)
 void ETSLexer::NextToken(NextTokenFlags flags)
 {
+    flags |= DefaultNextTokenFlags();
     ETSKeywords kws(this, static_cast<NextTokenFlags>(flags & ~NextTokenFlags::KEYWORD_TO_IDENT));
     Lexer::NextToken(&kws);
 }
diff --git a/ets2panda/lexer/keywordsUtil.cpp b/ets2panda/lexer/keywordsUtil.cpp
index f3bdff0a97c7bfff47e270c1a40b79abe5676fac..1614d719d32220f31ca13c69235b79db6539e651 100644
--- a/ets2panda/lexer/keywordsUtil.cpp
+++ b/ets2panda/lexer/keywordsUtil.cpp
@@ -231,7 +231,8 @@ void KeywordsUtil::ScanIdContinue()
 
         size_t cpSize {};
         auto cp = Iterator().PeekCp(&cpSize);
-        if (!IsIdentifierPart(cp)) {
+        if (!IsIdentifierPart(cp) &&
+            (cp != LEX_CHAR_PERCENT || (Flags() & NextTokenFlags::CHAR_PERCENT_ALLOWED) == 0)) {
             break;
         }
 
diff --git a/ets2panda/lexer/lexer.h b/ets2panda/lexer/lexer.h
index 4f5031912247c98c12da9f312d5cb32d3056afc7..464dd2a0e64e47ff388391efaea2b3cc5dc14ffc 100644
--- a/ets2panda/lexer/lexer.h
+++ b/ets2panda/lexer/lexer.h
@@ -40,6 +40,7 @@ enum class NextTokenFlags : uint32_t {
     NUMERIC_SEPARATOR_ALLOWED = 1U << 1U,
     BIGINT_ALLOWED = 1U << 2U,
     UNARY_MINUS = 1U << 3U,
+    CHAR_PERCENT_ALLOWED = 1U << 4U,
 };
 
 class LexerPosition {
@@ -269,6 +270,16 @@ public:
         return GetToken().Start();
     }
 
+    NextTokenFlags DefaultNextTokenFlags() const
+    {
+        return defaultNextTokenFlags;
+    }
+
+    void SetDefaultNextTokenFlags(NextTokenFlags flags)
+    {
+        defaultNextTokenFlags = flags;
+    }
+
 protected:
     void NextToken(Keywords *kws);
     ArenaAllocator *Allocator();
@@ -377,11 +388,11 @@ protected:
 private:
     TemplateLiteralParserContext *tlCtx_ {};
     ArenaAllocator *allocator_;
-    Keywords *kws_ {};
     const parser::ParserContext *parserContext_;
     util::StringView source_;
     LexerPosition pos_;
     util::DiagnosticEngine &diagnosticEngine_;
+    NextTokenFlags defaultNextTokenFlags = NextTokenFlags::NONE;
 };
 
 class TemplateLiteralParserContext {
diff --git a/ets2panda/parser/ETSparser.cpp b/ets2panda/parser/ETSparser.cpp
index d6c04b52feca3475996e137338f2d1570b3ad15a..edc97d8ffb091b48e64c1b7714aea939708265f9 100644
--- a/ets2panda/parser/ETSparser.cpp
+++ b/ets2panda/parser/ETSparser.cpp
@@ -108,6 +108,9 @@ std::unique_ptr<lexer::Lexer> ETSParser::InitLexer(const SourceFile &sourceFile)
 {
     GetProgram()->SetSource(sourceFile);
     auto lexer = std::make_unique<lexer::ETSLexer>(&GetContext(), DiagnosticEngine());
+    if (sourceFile.isExternalSourceImport) {
+        lexer->SetDefaultNextTokenFlags(lexer::NextTokenFlags::CHAR_PERCENT_ALLOWED);
+    }
     SetLexer(lexer.get());
     return lexer;
 }
@@ -314,6 +317,7 @@ void ETSParser::ParseParseListElement(const util::ImportPathManager::ParseInfo &
     auto src = importData.HasSpecifiedDeclPath() ? importData.declPath : importData.resolvedSource;
     ES2PANDA_ASSERT(!extSrc.empty());
     SourceFile sf {src, extSrc, importData.resolvedSource, false, importData.HasSpecifiedDeclPath()};
+    sf.isExternalSourceImport = importData.IsExternalSourceImport();
     parser::Program *newProg = ParseSource(sf);
     ES2PANDA_ASSERT(newProg != nullptr);
     if (!importData.IsImplicitPackageImported() || newProg->IsPackage()) {