diff --git a/src/plugins/qmakeprojectmanager/makefileparse.cpp b/src/plugins/qmakeprojectmanager/makefileparse.cpp
index b5a6d82a1f9..de8ff427863 100644
--- a/src/plugins/qmakeprojectmanager/makefileparse.cpp
+++ b/src/plugins/qmakeprojectmanager/makefileparse.cpp
@@ -25,7 +25,13 @@ static QString findQMakeLine(const FilePath &makefile, const QString &key)
 {
     QFile fi(makefile.toString());
     if (fi.exists() && fi.open(QFile::ReadOnly)) {
+        static const QString cmakeLine("# CMAKE generated file: DO NOT EDIT!");
         QTextStream ts(&fi);
+        if (!ts.atEnd()) {
+            if (ts.readLine() == cmakeLine)
+                return {};
+            ts.seek(0);
+        }
         while (!ts.atEnd()) {
             const QString line = ts.readLine();
             if (line.startsWith(key))
@@ -48,7 +54,7 @@ void MakeFileParse::parseArgs(const QString &args, const QString &project,
                               QList<QMakeAssignment> *assignments,
                               QList<QMakeAssignment> *afterAssignments)
 {
-    const QRegularExpression regExp(QLatin1String("^([^\\s\\+-]*)\\s*(\\+=|=|-=|~=)(.*)$"));
+    static const QRegularExpression regExp(QLatin1String("^([^\\s\\+-]*)\\s*(\\+=|=|-=|~=)(.*)$"));
     bool after = false;
     bool ignoreNext = false;
     m_unparsedArguments = args;
@@ -207,7 +213,7 @@ static FilePath findQMakeBinaryFromMakefile(const FilePath &makefile)
     QFile fi(makefile.toString());
     if (fi.exists() && fi.open(QFile::ReadOnly)) {
         QTextStream ts(&fi);
-        const QRegularExpression r1(QLatin1String("^QMAKE\\s*=(.*)$"));
+        static const QRegularExpression r1(QLatin1String("^QMAKE\\s*=(.*)$"));
         while (!ts.atEnd()) {
             QString line = ts.readLine();
             const QRegularExpressionMatch match = r1.match(line);
@@ -228,7 +234,9 @@ static FilePath findQMakeBinaryFromMakefile(const FilePath &makefile)
     return {};
 }
 
-MakeFileParse::MakeFileParse(const FilePath &makefile, Mode mode) : m_mode(mode)
+MakeFileParse::MakeFileParse(const FilePath &makefile, Mode mode,
+                             std::optional<FilePath> projectPath)
+    : m_mode(mode)
 {
     qCDebug(logging()) << "Parsing makefile" << makefile;
     if (!makefile.exists()) {
@@ -237,10 +245,6 @@ MakeFileParse::MakeFileParse(const FilePath &makefile, Mode mode) : m_mode(mode)
         return;
     }
 
-    // Qt Version!
-    m_qmakePath = findQMakeBinaryFromMakefile(makefile);
-    qCDebug(logging()) << "  qmake:" << m_qmakePath;
-
     QString project = findQMakeLine(makefile, QLatin1String("# Project:")).trimmed();
     if (project.isEmpty()) {
         m_state = CouldNotParse;
@@ -254,6 +258,14 @@ MakeFileParse::MakeFileParse(const FilePath &makefile, Mode mode) : m_mode(mode)
     // Src Pro file
     m_srcProFile = makefile.parentDir().resolvePath(project);
     qCDebug(logging()) << "  source .pro file:" << m_srcProFile;
+    if (projectPath && m_srcProFile != *projectPath) { // shortcut when importing
+        m_state = Okay;
+        return;
+    }
+
+    // Qt Version!
+    m_qmakePath = findQMakeBinaryFromMakefile(makefile);
+    qCDebug(logging()) << "  qmake:" << m_qmakePath;
 
     QString command = findQMakeLine(makefile, QLatin1String("# Command:")).trimmed();
     if (command.isEmpty()) {
diff --git a/src/plugins/qmakeprojectmanager/makefileparse.h b/src/plugins/qmakeprojectmanager/makefileparse.h
index 20bef6ce246..597ce717d13 100644
--- a/src/plugins/qmakeprojectmanager/makefileparse.h
+++ b/src/plugins/qmakeprojectmanager/makefileparse.h
@@ -7,6 +7,8 @@
 #include <qtsupport/baseqtversion.h>
 #include <utils/filepath.h>
 
+#include <optional>
+
 namespace QmakeProjectManager {
 namespace Internal {
 
@@ -21,7 +23,8 @@ class MakeFileParse
 {
 public:
     enum class Mode { FilterKnownConfigValues, DoNotFilterKnownConfigValues };
-    MakeFileParse(const Utils::FilePath &makefile, Mode mode);
+    MakeFileParse(const Utils::FilePath &makefile, Mode mode,
+                  std::optional<Utils::FilePath> projectFile = std::nullopt);
 
     enum MakefileState { MakefileMissing, CouldNotParse, Okay };
 
diff --git a/src/plugins/qmakeprojectmanager/qmakeprojectimporter.cpp b/src/plugins/qmakeprojectmanager/qmakeprojectimporter.cpp
index 832fb1a6809..ccd78c243a2 100644
--- a/src/plugins/qmakeprojectmanager/qmakeprojectimporter.cpp
+++ b/src/plugins/qmakeprojectmanager/qmakeprojectimporter.cpp
@@ -97,7 +97,7 @@ QList<void *> QmakeProjectImporter::examineDirectory(const FilePath &importPath,
         qCDebug(logs) << "  Parsing makefile" << file;
         // find interesting makefiles
         const FilePath makefile = importPath / file;
-        MakeFileParse parse(makefile, MakeFileParse::Mode::FilterKnownConfigValues);
+        MakeFileParse parse(makefile, MakeFileParse::Mode::FilterKnownConfigValues, projectFilePath());
         if (parse.makeFileState() != MakeFileParse::Okay) {
             qCDebug(logs) << "  Parsing the makefile failed" << makefile;
             continue;
@@ -108,7 +108,7 @@ QList<void *> QmakeProjectImporter::examineDirectory(const FilePath &importPath,
         }
 
         data->canonicalQmakeBinary = parse.qmakePath().canonicalPath();
-        if (data->canonicalQmakeBinary.isEmpty()) {
+        if (!data->canonicalQmakeBinary.exists()) {
             qCDebug(logs) << "  " << parse.qmakePath() << "doesn't exist anymore";
             continue;
         }