diff --git a/lib/cppcheck.cpp b/lib/cppcheck.cpp
index a80148debdf..1de4ad37732 100644
--- a/lib/cppcheck.cpp
+++ b/lib/cppcheck.cpp
@@ -583,14 +583,13 @@ unsigned int CppCheck::check(const std::string &path)
         return mExitCode;
     }
 
-    std::ifstream fin(path);
-    return checkFile(Path::simplifyPath(path), emptyString, fin);
+    return checkFile(Path::simplifyPath(path), emptyString);
 }
 
 unsigned int CppCheck::check(const std::string &path, const std::string &content)
 {
     std::istringstream iss(content);
-    return checkFile(Path::simplifyPath(path), emptyString, iss);
+    return checkFile(Path::simplifyPath(path), emptyString, &iss);
 }
 
 unsigned int CppCheck::check(const ImportProject::FileSettings &fs)
@@ -615,13 +614,20 @@ unsigned int CppCheck::check(const ImportProject::FileSettings &fs)
         temp.mSettings.includePaths.insert(temp.mSettings.includePaths.end(), fs.systemIncludePaths.cbegin(), fs.systemIncludePaths.cend());
         return temp.check(Path::simplifyPath(fs.filename));
     }
-    std::ifstream fin(fs.filename);
-    const unsigned int returnValue = temp.checkFile(Path::simplifyPath(fs.filename), fs.cfg, fin);
+    const unsigned int returnValue = temp.checkFile(Path::simplifyPath(fs.filename), fs.cfg);
     mSettings.nomsg.addSuppressions(temp.mSettings.nomsg.getSuppressions());
     return returnValue;
 }
 
-unsigned int CppCheck::checkFile(const std::string& filename, const std::string &cfgname, std::istream& fileStream)
+static simplecpp::TokenList createTokenList(const std::string& filename, std::vector<std::string>& files, simplecpp::OutputList* outputList, std::istream* fileStream)
+{
+    if (fileStream)
+        return {*fileStream, files, filename, outputList};
+
+    return {filename, files, outputList};
+}
+
+unsigned int CppCheck::checkFile(const std::string& filename, const std::string &cfgname, std::istream* fileStream)
 {
     mExitCode = 0;
 
@@ -663,7 +669,7 @@ unsigned int CppCheck::checkFile(const std::string& filename, const std::string
 
         simplecpp::OutputList outputList;
         std::vector<std::string> files;
-        simplecpp::TokenList tokens1(fileStream, files, filename, &outputList);
+        simplecpp::TokenList tokens1 = createTokenList(filename, files, &outputList, fileStream);
 
         // If there is a syntax error, report it and stop
         for (const simplecpp::Output &output : outputList) {
diff --git a/lib/cppcheck.h b/lib/cppcheck.h
index 46ab23ae040..24b8b412355 100644
--- a/lib/cppcheck.h
+++ b/lib/cppcheck.h
@@ -159,7 +159,7 @@ class CPPCHECKLIB CppCheck : ErrorLogger {
      * @param fileStream stream the file content can be read from
      * @return number of errors found
      */
-    unsigned int checkFile(const std::string& filename, const std::string &cfgname, std::istream& fileStream);
+    unsigned int checkFile(const std::string& filename, const std::string &cfgname, std::istream* fileStream = nullptr);
 
     /**
      * @brief Check raw tokens