diff --git a/src/plugins/nim/project/nimprojectnode.cpp b/src/plugins/nim/project/nimprojectnode.cpp
index c4c306cdf3a..5c22cea185f 100644
--- a/src/plugins/nim/project/nimprojectnode.cpp
+++ b/src/plugins/nim/project/nimprojectnode.cpp
@@ -57,21 +57,6 @@ QList<ProjectAction> NimProjectNode::supportedActions(Node *node) const
     }
 }
 
-bool NimProjectNode::addSubProjects(const QStringList &)
-{
-    return false;
-}
-
-bool NimProjectNode::canAddSubProject(const QString &) const
-{
-    return false;
-}
-
-bool NimProjectNode::removeSubProjects(const QStringList &)
-{
-    return false;
-}
-
 bool NimProjectNode::addFiles(const QStringList &filePaths, QStringList *)
 {
     return m_project.addFiles(filePaths);
diff --git a/src/plugins/nim/project/nimprojectnode.h b/src/plugins/nim/project/nimprojectnode.h
index 9c124824fba..ba4dd634153 100644
--- a/src/plugins/nim/project/nimprojectnode.h
+++ b/src/plugins/nim/project/nimprojectnode.h
@@ -39,9 +39,6 @@ public:
     NimProjectNode(NimProject &project, const Utils::FileName &projectFilePath);
 
     QList<ProjectExplorer::ProjectAction> supportedActions(Node *node) const override;
-    bool canAddSubProject(const QString &) const override;
-    bool addSubProjects(const QStringList &) override;
-    bool removeSubProjects(const QStringList &) override;
     bool addFiles(const QStringList &filePaths, QStringList *) override;
     bool removeFiles(const QStringList &filePaths, QStringList *) override;
     bool deleteFiles(const QStringList &) override;
diff --git a/src/plugins/projectexplorer/jsonwizard/jsonsummarypage.cpp b/src/plugins/projectexplorer/jsonwizard/jsonsummarypage.cpp
index 909f690b227..5f02bc7779d 100644
--- a/src/plugins/projectexplorer/jsonwizard/jsonsummarypage.cpp
+++ b/src/plugins/projectexplorer/jsonwizard/jsonsummarypage.cpp
@@ -175,7 +175,7 @@ void JsonSummaryPage::addToProject(const JsonWizard::GeneratorFiles &files)
     if (!folder)
         return;
     if (kind == IWizardFactory::ProjectWizard) {
-        if (!static_cast<ProjectNode *>(folder)->addSubProjects(QStringList(generatedProject))) {
+        if (!static_cast<ProjectNode *>(folder)->addSubProject(generatedProject)) {
             QMessageBox::critical(m_wizard, tr("Failed to Add to Project"),
                                   tr("Failed to add subproject \"%1\"\nto project \"%2\".")
                                   .arg(QDir::toNativeSeparators(generatedProject))
diff --git a/src/plugins/projectexplorer/projectexplorer.cpp b/src/plugins/projectexplorer/projectexplorer.cpp
index 8bfb8d4e6b7..c34c3d5476f 100644
--- a/src/plugins/projectexplorer/projectexplorer.cpp
+++ b/src/plugins/projectexplorer/projectexplorer.cpp
@@ -3212,7 +3212,7 @@ void ProjectExplorerPluginPrivate::removeProject()
         RemoveFileDialog removeFileDialog(subProjectNode->filePath().toString(), ICore::mainWindow());
         removeFileDialog.setDeleteFileVisible(false);
         if (removeFileDialog.exec() == QDialog::Accepted)
-            projectNode->removeSubProjects(QStringList() << subProjectNode->filePath().toString());
+            projectNode->removeSubProject(subProjectNode->filePath().toString());
     }
 }
 
diff --git a/src/plugins/projectexplorer/projectfilewizardextension.cpp b/src/plugins/projectexplorer/projectfilewizardextension.cpp
index bc8a04382c3..c7bf50e2467 100644
--- a/src/plugins/projectexplorer/projectfilewizardextension.cpp
+++ b/src/plugins/projectexplorer/projectfilewizardextension.cpp
@@ -181,7 +181,7 @@ bool ProjectFileWizardExtension::processProject(
     if (!folder)
         return true;
     if (m_context->wizard->kind() == IWizardFactory::ProjectWizard) {
-        if (!static_cast<ProjectNode *>(folder)->addSubProjects(QStringList(generatedProject))) {
+        if (!static_cast<ProjectNode *>(folder)->addSubProject(generatedProject)) {
             *errorMessage = tr("Failed to add subproject \"%1\"\nto project \"%2\".")
                             .arg(generatedProject).arg(folder->filePath().toUserOutput());
             return false;
diff --git a/src/plugins/projectexplorer/projectnodes.cpp b/src/plugins/projectexplorer/projectnodes.cpp
index b9491687c21..8557b99003f 100644
--- a/src/plugins/projectexplorer/projectnodes.cpp
+++ b/src/plugins/projectexplorer/projectnodes.cpp
@@ -720,15 +720,15 @@ bool ProjectNode::canAddSubProject(const QString &proFilePath) const
     return false;
 }
 
-bool ProjectNode::addSubProjects(const QStringList &proFilePaths)
+bool ProjectNode::addSubProject(const QString &proFilePath)
 {
-    Q_UNUSED(proFilePaths)
+    Q_UNUSED(proFilePath)
     return false;
 }
 
-bool ProjectNode::removeSubProjects(const QStringList &proFilePaths)
+bool ProjectNode::removeSubProject(const QString &proFilePath)
 {
-    Q_UNUSED(proFilePaths)
+    Q_UNUSED(proFilePath)
     return false;
 }
 
diff --git a/src/plugins/projectexplorer/projectnodes.h b/src/plugins/projectexplorer/projectnodes.h
index dd0c5d9afb6..fb17b4806e8 100644
--- a/src/plugins/projectexplorer/projectnodes.h
+++ b/src/plugins/projectexplorer/projectnodes.h
@@ -278,8 +278,8 @@ public:
     QString vcsTopic() const;
 
     virtual bool canAddSubProject(const QString &proFilePath) const;
-    virtual bool addSubProjects(const QStringList &proFilePaths);
-    virtual bool removeSubProjects(const QStringList &proFilePaths);
+    virtual bool addSubProject(const QString &proFile);
+    virtual bool removeSubProject(const QString &proFilePath);
 
     bool addFiles(const QStringList &filePaths, QStringList *notAdded = 0) override;
     bool removeFiles(const QStringList &filePaths, QStringList *notRemoved = 0) override;
diff --git a/src/plugins/qmakeprojectmanager/qmakenodes.cpp b/src/plugins/qmakeprojectmanager/qmakenodes.cpp
index 1f19b76a9ed..b2ea316330b 100644
--- a/src/plugins/qmakeprojectmanager/qmakenodes.cpp
+++ b/src/plugins/qmakeprojectmanager/qmakenodes.cpp
@@ -148,16 +148,16 @@ bool QmakePriFileNode::canAddSubProject(const QString &proFilePath) const
     return pri ? pri->canAddSubProject(proFilePath) : false;
 }
 
-bool QmakePriFileNode::addSubProjects(const QStringList &proFilePaths)
+bool QmakePriFileNode::addSubProject(const QString &proFilePath)
 {
     QmakePriFile *pri = priFile();
-    return pri ? pri->addSubProjects(proFilePaths) : false;
+    return pri ? pri->addSubProject(proFilePath) : false;
 }
 
-bool QmakePriFileNode::removeSubProjects(const QStringList &proFilePaths)
+bool QmakePriFileNode::removeSubProject(const QString &proFilePath)
 {
     QmakePriFile *pri = priFile();
-    return pri ? pri->removeSubProjects(proFilePaths) : false;
+    return pri ? pri->removeSubProjects(proFilePath) : false;
 }
 
 bool QmakePriFileNode::addFiles(const QStringList &filePaths, QStringList *notAdded)
diff --git a/src/plugins/qmakeprojectmanager/qmakenodes.h b/src/plugins/qmakeprojectmanager/qmakenodes.h
index 89f6039dd6e..b04751809ac 100644
--- a/src/plugins/qmakeprojectmanager/qmakenodes.h
+++ b/src/plugins/qmakeprojectmanager/qmakenodes.h
@@ -53,8 +53,8 @@ public:
 
     bool canAddSubProject(const QString &proFilePath) const override;
 
-    bool addSubProjects(const QStringList &proFilePaths) override;
-    bool removeSubProjects(const QStringList &proFilePaths) override;
+    bool addSubProject(const QString &proFilePath) override;
+    bool removeSubProject(const QString &proFilePath) override;
 
     bool addFiles(const QStringList &filePaths, QStringList *notAdded = nullptr) override;
     bool removeFiles(const QStringList &filePaths, QStringList *notRemoved = nullptr) override;
diff --git a/src/plugins/qmakeprojectmanager/qmakeparsernodes.cpp b/src/plugins/qmakeprojectmanager/qmakeparsernodes.cpp
index 8b555df827a..5abc263c6da 100644
--- a/src/plugins/qmakeprojectmanager/qmakeparsernodes.cpp
+++ b/src/plugins/qmakeprojectmanager/qmakeparsernodes.cpp
@@ -474,13 +474,11 @@ static QString simplifyProFilePath(const QString &proFilePath)
     return proFilePath;
 }
 
-bool QmakePriFile::addSubProjects(const QStringList &proFilePaths)
+bool QmakePriFile::addSubProject(const QString &proFile)
 {
     QStringList uniqueProFilePaths;
-    foreach (const QString &proFile, proFilePaths) {
-        if (!m_recursiveEnumerateFiles.contains(FileName::fromString(proFile)))
-            uniqueProFilePaths.append(simplifyProFilePath(proFile));
-    }
+    if (!m_recursiveEnumerateFiles.contains(FileName::fromString(proFile)))
+        uniqueProFilePaths.append(simplifyProFilePath(proFile));
 
     QStringList failedFiles;
     changeFiles(QLatin1String(Constants::PROFILE_MIMETYPE), uniqueProFilePaths, &failedFiles, AddToProFile);
@@ -488,10 +486,10 @@ bool QmakePriFile::addSubProjects(const QStringList &proFilePaths)
     return failedFiles.isEmpty();
 }
 
-bool QmakePriFile::removeSubProjects(const QStringList &proFilePaths)
+bool QmakePriFile::removeSubProjects(const QString &proFilePath)
 {
     QStringList failedOriginalFiles;
-    changeFiles(QLatin1String(Constants::PROFILE_MIMETYPE), proFilePaths, &failedOriginalFiles, RemoveFromProFile);
+    changeFiles(QLatin1String(Constants::PROFILE_MIMETYPE), QStringList(proFilePath), &failedOriginalFiles, RemoveFromProFile);
 
     QStringList simplifiedProFiles = Utils::transform(failedOriginalFiles, &simplifyProFilePath);
 
diff --git a/src/plugins/qmakeprojectmanager/qmakeparsernodes.h b/src/plugins/qmakeprojectmanager/qmakeparsernodes.h
index 228a92876eb..a1ad876f76a 100644
--- a/src/plugins/qmakeprojectmanager/qmakeparsernodes.h
+++ b/src/plugins/qmakeprojectmanager/qmakeparsernodes.h
@@ -134,8 +134,8 @@ public:
     // ProjectNode interface
     virtual bool canAddSubProject(const QString &proFilePath) const;
 
-    virtual bool addSubProjects(const QStringList &proFilePaths);
-    virtual bool removeSubProjects(const QStringList &proFilePaths);
+    virtual bool addSubProject(const QString &proFile);
+    virtual bool removeSubProjects(const QString &proFilePath);
 
     virtual bool addFiles(const QStringList &filePaths, QStringList *notAdded = nullptr);
     virtual bool removeFiles(const QStringList &filePaths, QStringList *notRemoved = nullptr);