diff --git a/src/plugins/cmakeprojectmanager/cmakebuildinfo.h b/src/plugins/cmakeprojectmanager/cmakebuildinfo.h
index 52e31ba691c..45fc90594a2 100644
--- a/src/plugins/cmakeprojectmanager/cmakebuildinfo.h
+++ b/src/plugins/cmakeprojectmanager/cmakebuildinfo.h
@@ -55,6 +55,16 @@ public:
         configuration = bc->cmakeConfiguration();
     }
 
+    bool operator==(const BuildInfo &o) const final
+    {
+        if (!ProjectExplorer::BuildInfo::operator==(o))
+            return false;
+
+        auto other = static_cast<const CMakeBuildInfo *>(&o);
+        return sourceDirectory == other->sourceDirectory
+                && configuration == other->configuration;
+    }
+
     QString sourceDirectory;
     CMakeConfig configuration;
 };
diff --git a/src/plugins/cmakeprojectmanager/cmakeconfigitem.cpp b/src/plugins/cmakeprojectmanager/cmakeconfigitem.cpp
index 761244d42ee..cd4bea5c093 100644
--- a/src/plugins/cmakeprojectmanager/cmakeconfigitem.cpp
+++ b/src/plugins/cmakeprojectmanager/cmakeconfigitem.cpp
@@ -177,4 +177,10 @@ QString CMakeConfigItem::toString() const
     return QString::fromUtf8(key) + QLatin1Char(':') + typeStr + QLatin1Char('=') + QString::fromUtf8(value);
 }
 
+bool CMakeConfigItem::operator==(const CMakeConfigItem &o) const
+{
+    // type, isAdvanced and documentation do not matter for a match!
+    return o.key == key && o.value == value;
+}
+
 } // namespace CMakeProjectManager
diff --git a/src/plugins/cmakeprojectmanager/cmakeconfigitem.h b/src/plugins/cmakeprojectmanager/cmakeconfigitem.h
index f275465e4c2..70bacbb5cb1 100644
--- a/src/plugins/cmakeprojectmanager/cmakeconfigitem.h
+++ b/src/plugins/cmakeprojectmanager/cmakeconfigitem.h
@@ -53,6 +53,8 @@ public:
     static CMakeConfigItem fromString(const QString &s);
     QString toString() const;
 
+    bool operator==(const CMakeConfigItem &o) const;
+
     QByteArray key;
     Type type = STRING;
     bool isAdvanced = false;
diff --git a/src/plugins/projectexplorer/buildinfo.h b/src/plugins/projectexplorer/buildinfo.h
index ddda9363a4a..e2163097e6d 100644
--- a/src/plugins/projectexplorer/buildinfo.h
+++ b/src/plugins/projectexplorer/buildinfo.h
@@ -51,9 +51,10 @@ public:
     Core::Id kitId;
     BuildConfiguration::BuildType buildType = BuildConfiguration::Unknown;
 
-    bool operator==(const BuildInfo &o)
+    virtual bool operator==(const BuildInfo &o) const
     {
-        return displayName == o.displayName && typeName == o.typeName
+        return m_factory == o.m_factory
+                && displayName == o.displayName && typeName == o.typeName
                 && buildDirectory == o.buildDirectory && kitId == o.kitId
                 && buildType == o.buildType;
     }
diff --git a/src/plugins/qmakeprojectmanager/qmakebuildinfo.h b/src/plugins/qmakeprojectmanager/qmakebuildinfo.h
index 41e3eeb507c..97a8681852c 100644
--- a/src/plugins/qmakeprojectmanager/qmakebuildinfo.h
+++ b/src/plugins/qmakeprojectmanager/qmakebuildinfo.h
@@ -44,11 +44,15 @@ public:
     QString makefile;
     QMakeStepConfig config;
 
-    bool operator==(const QmakeBuildInfo &o)
+    bool operator==(const BuildInfo &o) const final
     {
-        return ProjectExplorer::BuildInfo::operator==(o)
-                && additionalArguments == o.additionalArguments
-                && config == o.config;
+        if (!ProjectExplorer::BuildInfo::operator==(o))
+            return false;
+
+        auto other = static_cast<const QmakeBuildInfo *>(&o);
+        return additionalArguments == other->additionalArguments
+                && makefile == other->makefile
+                && config == other->config;
     }
 
     QList<ProjectExplorer::Task> reportIssues(const QString &projectPath,