diff --git a/kdevplatform/project/debug.cpp b/kdevplatform/project/debug.cpp
--- a/kdevplatform/project/debug.cpp
+++ b/kdevplatform/project/debug.cpp
@@ -21,10 +21,6 @@
 
 // TODO: ecm_qt_declare_logging_category only supports one category
 // so generate two separate files with a wrapper debug.h, or have code include explicit matching header?
-#if QT_VERSION >= 0x050500
 const QtMsgType defaultMsgType = QtInfoMsg;
-#else
-const QtMsgType defaultMsgType = QtWarningMsg;
-#endif
 Q_LOGGING_CATEGORY(PROJECT, "kdevplatform.project", defaultMsgType)
 Q_LOGGING_CATEGORY(FILEMANAGER, "kdevplatform.filemanager", defaultMsgType)
diff --git a/kdevplatform/util/duchainify/main.cpp b/kdevplatform/util/duchainify/main.cpp
--- a/kdevplatform/util/duchainify/main.cpp
+++ b/kdevplatform/util/duchainify/main.cpp
@@ -58,9 +58,7 @@
     Q_UNUSED(context);
 
     switch (type) {
-#if QT_VERSION >= 0x050500
         case QtInfoMsg: // fall-through
-#endif
         case QtDebugMsg:
             if(verbose)
                 std::cerr << qPrintable(msg) << std::endl;
diff --git a/plugins/clang/util/clangdebug.cpp b/plugins/clang/util/clangdebug.cpp
--- a/plugins/clang/util/clangdebug.cpp
+++ b/plugins/clang/util/clangdebug.cpp
@@ -27,11 +27,7 @@
 #include <language/editor/documentcursor.h>
 #include <language/editor/documentrange.h>
 
-#if QT_VERSION >= 0x050500
 const QtMsgType defaultMsgType = QtInfoMsg;
-#else
-const QtMsgType defaultMsgType = QtWarningMsg;
-#endif
 Q_LOGGING_CATEGORY(KDEV_CLANG, "kdevelop.languages.clang", defaultMsgType)
 
 using namespace KDevelop;
diff --git a/plugins/git/gitplugin.cpp b/plugins/git/gitplugin.cpp
--- a/plugins/git/gitplugin.cpp
+++ b/plugins/git/gitplugin.cpp
@@ -1051,11 +1051,7 @@
 
     for (int i=0; i<lines.count(); ++i) {
 //         qCDebug(PLUGIN_GIT) << "line:" << s;
-#if QT_VERSION >= 0x050500
         if (rx_com.match(lines[i]).hasMatch()) {
-#else
-        if (rx_com.match(lines[i].toString()).hasMatch()) {
-#endif
 //             qCDebug(PLUGIN_GIT) << "MATCH COMMIT";
             item.setCommit(lines[++i].toString());
             item.setAuthor(lines[++i].toString());
diff --git a/plugins/qthelp/qthelpdocumentation.cpp b/plugins/qthelp/qthelpdocumentation.cpp
--- a/plugins/qthelp/qthelpdocumentation.cpp
+++ b/plugins/qthelp/qthelpdocumentation.cpp
@@ -40,64 +40,6 @@
 
 using namespace KDevelop;
 
-namespace {
-#if QT_VERSION >= 0x050500
-int indexOf(const QString& str, const QRegularExpression& re, int from, QRegularExpressionMatch* rmatch)
-{
-    return str.indexOf(re, from, rmatch);
-}
-
-int lastIndexOf(const QString& str, const QRegularExpression& re, int from, QRegularExpressionMatch* rmatch)
-{
-    return str.lastIndexOf(re, from, rmatch);
-}
-#else
-int indexOf(const QString& str, const QRegularExpression& re, int from, QRegularExpressionMatch* rmatch)
-{
-    if (!re.isValid()) {
-        qCWarning(QTHELP) << "QString::indexOf: invalid QRegularExpression object";
-        return -1;
-    }
-
-    QRegularExpressionMatch match = re.match(str, from);
-    if (match.hasMatch()) {
-        const int ret = match.capturedStart();
-        if (rmatch)
-            *rmatch = qMove(match);
-        return ret;
-    }
-
-    return -1;
-}
-
-int lastIndexOf(const QString &str, const QRegularExpression &re, int from, QRegularExpressionMatch *rmatch)
-{
-    if (!re.isValid()) {
-        qCWarning(QTHELP) << "QString::lastIndexOf: invalid QRegularExpression object";
-        return -1;
-    }
-
-    int endpos = (from < 0) ? (str.size() + from + 1) : (from + 1);
-    QRegularExpressionMatchIterator iterator = re.globalMatch(str);
-    int lastIndex = -1;
-    while (iterator.hasNext()) {
-        QRegularExpressionMatch match = iterator.next();
-        int start = match.capturedStart();
-        if (start < endpos) {
-            lastIndex = start;
-            if (rmatch)
-                *rmatch = qMove(match);
-        } else {
-            break;
-        }
-    }
-
-    return lastIndex;
-}
-#endif
-
-}
-
 QtHelpProviderAbstract* QtHelpDocumentation::s_provider=nullptr;
 
 QtHelpDocumentation::QtHelpDocumentation(const QString& name, const QMap<QString, QUrl>& info)
@@ -126,7 +68,7 @@
 
     const QRegularExpression findFragment(exp);
     QRegularExpressionMatch findFragmentMatch;
-    int pos = indexOf(dataString, findFragment, 0, &findFragmentMatch);
+    int pos = dataString.indexOf(findFragment, 0, &findFragmentMatch);
 
     if(fragment.isEmpty()) {
         pos = 0;
@@ -158,7 +100,7 @@
             const QString newLineRegExp = QStringLiteral ("< br / > | < / p >").replace(' ', optionalSpace);
             const QRegularExpression lastNewLine(newLineRegExp);
             QRegularExpressionMatch match;
-            const int newEnd = lastIndexOf(dataString, lastNewLine, endPos, &match);
+            const int newEnd = dataString.lastIndexOf(lastNewLine, endPos, &match);
             if(match.isValid() && newEnd > pos)
                 endPos = newEnd + match.capturedLength();
         }