diff --git a/src/libs/utils/fileutils.cpp b/src/libs/utils/fileutils.cpp
index 647318a2e52..71bfd96aff5 100644
--- a/src/libs/utils/fileutils.cpp
+++ b/src/libs/utils/fileutils.cpp
@@ -787,6 +787,34 @@ QString FilePath::completeBaseName() const
     return name.left(name.lastIndexOf('.'));
 }
 
+/// \returns the suffix (extension) of the file.
+///
+/// The suffix consists of all characters in the file after
+/// (but not including) the last '.'.
+
+QString FilePath::suffix() const
+{
+    const QString &name = fileName();
+    const int index = name.lastIndexOf('.');
+    if (index >= 0)
+        return name.mid(index + 1);
+    return {};
+}
+
+/// \returns the complete suffix (extension) of the file.
+///
+/// The complete suffix consists of all characters in the file after
+/// (but not including) the first '.'.
+
+QString FilePath::completeSuffix() const
+{
+    const QString &name = fileName();
+    const int index = name.indexOf('.');
+    if (index >= 0)
+        return name.mid(index + 1);
+    return {};
+}
+
 void FilePath::setScheme(const QString &scheme)
 {
     QTC_CHECK(!scheme.contains('/'));
diff --git a/src/libs/utils/fileutils.h b/src/libs/utils/fileutils.h
index a6987633d38..431e9ec0c66 100644
--- a/src/libs/utils/fileutils.h
+++ b/src/libs/utils/fileutils.h
@@ -106,6 +106,8 @@ public:
 
     QString baseName() const;
     QString completeBaseName() const;
+    QString suffix() const;
+    QString completeSuffix() const;
 
     QString scheme() const { return m_scheme; }
     void setScheme(const QString &scheme);
diff --git a/src/plugins/coreplugin/plugininstallwizard.cpp b/src/plugins/coreplugin/plugininstallwizard.cpp
index 16200daf3f9..fa7b120be4c 100644
--- a/src/plugins/coreplugin/plugininstallwizard.cpp
+++ b/src/plugins/coreplugin/plugininstallwizard.cpp
@@ -79,7 +79,7 @@ static QStringList libraryNameFilter()
 static bool hasLibSuffix(const FilePath &path)
 {
     return (HostOsInfo::isWindowsHost() && path.endsWith(".dll"))
-           || (HostOsInfo::isLinuxHost() && path.toFileInfo().completeSuffix().startsWith(".so"))
+           || (HostOsInfo::isLinuxHost() && path.completeSuffix().startsWith(".so"))
            || (HostOsInfo::isMacHost() && path.endsWith(".dylib"));
 }
 
diff --git a/src/plugins/modeleditor/modelindexer.cpp b/src/plugins/modeleditor/modelindexer.cpp
index cc4fceeb5c5..86ff0230d95 100644
--- a/src/plugins/modeleditor/modelindexer.cpp
+++ b/src/plugins/modeleditor/modelindexer.cpp
@@ -470,7 +470,7 @@ QString ModelIndexer::findFirstModel(ProjectExplorer::FolderNode *folderNode,
     if (!mimeType.isValid())
         return QString();
     foreach (ProjectExplorer::FileNode *fileNode, folderNode->fileNodes()) {
-        if (mimeType.suffixes().contains(fileNode->filePath().toFileInfo().completeSuffix()))
+        if (mimeType.suffixes().contains(fileNode->filePath().completeSuffix()))
             return fileNode->filePath().toString();
     }
     foreach (ProjectExplorer::FolderNode *subFolderNode, folderNode->folderNodes()) {
diff --git a/src/plugins/projectexplorer/projectmodels.cpp b/src/plugins/projectexplorer/projectmodels.cpp
index 425f53548d4..d701a60ca26 100644
--- a/src/plugins/projectexplorer/projectmodels.cpp
+++ b/src/plugins/projectexplorer/projectmodels.cpp
@@ -212,7 +212,7 @@ bool FlatModel::setData(const QModelIndex &index, const QVariant &value, int rol
 
     // The base name of the file was changed. Go look for other files with the same base name
     // and offer to rename them as well.
-    if (orgFilePath != newFilePath && orgFileInfo.suffix() == newFilePath.toFileInfo().suffix()) {
+    if (orgFilePath != newFilePath && orgFileInfo.suffix() == newFilePath.suffix()) {
         const QList<Node *> candidateNodes = ProjectTree::siblingsWithSameBaseName(node);
         if (!candidateNodes.isEmpty()) {
             const QMessageBox::StandardButton reply = QMessageBox::question(
@@ -225,7 +225,7 @@ bool FlatModel::setData(const QModelIndex &index, const QVariant &value, int rol
                 for (Node * const n : candidateNodes) {
                     QString targetFilePath = orgFileInfo.absolutePath() + '/'
                                              + newFilePath.completeBaseName();
-                    const QString suffix = n->filePath().toFileInfo().suffix();
+                    const QString suffix = n->filePath().suffix();
                     if (!suffix.isEmpty())
                         targetFilePath.append('.').append(suffix);
                     toRename.emplace_back(std::make_tuple(n, n->filePath(),
diff --git a/src/plugins/qmldesigner/components/componentcore/designeractionmanager.cpp b/src/plugins/qmldesigner/components/componentcore/designeractionmanager.cpp
index 1c865719ad3..369df95a322 100644
--- a/src/plugins/qmldesigner/components/componentcore/designeractionmanager.cpp
+++ b/src/plugins/qmldesigner/components/componentcore/designeractionmanager.cpp
@@ -861,8 +861,7 @@ bool singleSelectedAndUiFile(const SelectionContext &context)
     if (!designDocument)
         return false;
 
-    return designDocument->fileName().toFileInfo().completeSuffix()
-            == QLatin1String("ui.qml");
+    return designDocument->fileName().completeSuffix() == QLatin1String("ui.qml");
 }
 
 bool lowerAvailable(const SelectionContext &selectionState)
diff --git a/src/plugins/texteditor/highlighter.cpp b/src/plugins/texteditor/highlighter.cpp
index 1c36b115bab..ef6e4312f4f 100644
--- a/src/plugins/texteditor/highlighter.cpp
+++ b/src/plugins/texteditor/highlighter.cpp
@@ -172,7 +172,7 @@ Highlighter::Definitions Highlighter::definitionsForFileName(const Utils::FilePa
         = highlightRepository()->definitionsForFileName(fileName.fileName()).toList();
 
     if (definitions.size() > 1) {
-        const QString &fileExtension = fileName.toFileInfo().completeSuffix();
+        const QString &fileExtension = fileName.completeSuffix();
         const Definition &rememberedDefinition
             = fileExtension.isEmpty()
                   ? definitionForSetting(kDefinitionForFilePath,
@@ -192,7 +192,7 @@ void Highlighter::rememberDefinitionForDocument(const Highlighter::Definition &d
     if (!definition.isValid())
         return;
     const QString &mimeType = document->mimeType();
-    const QString &fileExtension = document->filePath().toFileInfo().completeSuffix();
+    const QString &fileExtension = document->filePath().completeSuffix();
     const QString &path = document->filePath().toFileInfo().canonicalFilePath();
     QSettings *settings = Core::ICore::settings();
     settings->beginGroup(Constants::HIGHLIGHTER_SETTINGS_CATEGORY);