diff --git a/src/plugins/android/androiddeploystep.cpp b/src/plugins/android/androiddeploystep.cpp
index 957df22b415..8916d46b17f 100644
--- a/src/plugins/android/androiddeploystep.cpp
+++ b/src/plugins/android/androiddeploystep.cpp
@@ -284,7 +284,7 @@ unsigned int AndroidDeployStep::remoteModificationTime(const QString &fullDestin
     process.waitForFinished(-1);
     if (process.error() != QProcess::UnknownError
             || process.exitCode() != 0)
-        return -1;
+        return 0;
     QByteArray output = process.readAll();
     output.replace("\r\n", "\n");
     QList<QByteArray> lines = output.split('\n');
diff --git a/src/plugins/cpptools/includeutils.cpp b/src/plugins/cpptools/includeutils.cpp
index 3d697974e7f..17bbf5c3190 100644
--- a/src/plugins/cpptools/includeutils.cpp
+++ b/src/plugins/cpptools/includeutils.cpp
@@ -423,7 +423,7 @@ int IncludeGroup::lineForNewInclude(const QString &newIncludeFileName,
         return -1;
 
     if (isSorted()) {
-        const Include newInclude(newIncludeFileName, QString(), -1, newIncludeType);
+        const Include newInclude(newIncludeFileName, QString(), 0, newIncludeType);
         const QList<Include>::const_iterator it = std::lower_bound(m_includes.begin(),
             m_includes.end(), newInclude, includeFileNamelessThen);
         if (it == m_includes.end())
diff --git a/src/plugins/debugger/debuggerprotocol.cpp b/src/plugins/debugger/debuggerprotocol.cpp
index 5e5ab738214..086e47fae50 100644
--- a/src/plugins/debugger/debuggerprotocol.cpp
+++ b/src/plugins/debugger/debuggerprotocol.cpp
@@ -50,7 +50,7 @@ uchar fromhex(uchar c)
         return 10 + c - 'a';
     if (c >= 'A' && c <= 'Z')
         return 10 + c - 'A';
-    return -1;
+    return UCHAR_MAX;
 }
 
 void skipCommas(const char *&from, const char *to)
@@ -141,7 +141,7 @@ QByteArray GdbMi::parseCString(const char *&from, const char *to)
                         uchar prod = 0;
                         while (true) {
                             uchar val = fromhex(c);
-                            if (val == uchar(-1))
+                            if (val == UCHAR_MAX)
                                 break;
                             prod = prod * 16 + val;
                             if (++chars == 3 || src == end)
diff --git a/src/plugins/debugger/qml/qmllivetextpreview.cpp b/src/plugins/debugger/qml/qmllivetextpreview.cpp
index f01a04738ca..4379aca42b5 100644
--- a/src/plugins/debugger/qml/qmllivetextpreview.cpp
+++ b/src/plugins/debugger/qml/qmllivetextpreview.cpp
@@ -642,7 +642,7 @@ void QmlLiveTextPreview::editorContentsChanged()
 
 void QmlLiveTextPreview::onAutomaticUpdateFailed()
 {
-    showSyncWarning(AutomaticUpdateFailed, QString(), -1, -1);
+    showSyncWarning(AutomaticUpdateFailed, QString(), UINT_MAX, UINT_MAX);
 }
 
 QList<int> QmlLiveTextPreview::objectReferencesForOffset(quint32 offset)
diff --git a/src/plugins/debugger/registerhandler.cpp b/src/plugins/debugger/registerhandler.cpp
index 71904f1ac47..4b068a9cade 100644
--- a/src/plugins/debugger/registerhandler.cpp
+++ b/src/plugins/debugger/registerhandler.cpp
@@ -293,7 +293,7 @@ static int bitWidthFromType(int type, int subType)
     return 0;
 }
 
-static const int TopLevelId = -1;
+static const uint TopLevelId = UINT_MAX;
 static bool isTopLevelItem(const QModelIndex &index)
 {
     return quintptr(index.internalId()) == quintptr(TopLevelId);