diff --git a/duchain/helpers.cpp b/duchain/helpers.cpp
--- a/duchain/helpers.cpp
+++ b/duchain/helpers.cpp
@@ -44,6 +44,8 @@
 #include <interfaces/ilanguagecontroller.h>
 #include <interfaces/idocumentcontroller.h>
 #include <interfaces/ipartcontroller.h>
+#include <interfaces/iruntimecontroller.h>
+#include <interfaces/iruntime.h>
 #include <util/path.h>
 
 #include <shell/partcontroller.h>
@@ -424,6 +426,14 @@
 
 QVector<QUrl> Helper::getSearchPaths(const QUrl& workingOnDocument)
 {
+    static bool first = true;
+    if (first) {
+        QObject::connect(ICore::self()->runtimeController(), &IRuntimeController::currentRuntimeChanged, ICore::self()->runtimeController(), [](){
+            QMutexLocker lock(&Helper::cacheMutex);
+            cachedSearchPaths.clear();
+        });
+    }
+
     QMutexLocker lock(&Helper::cacheMutex);
     QVector<QUrl> searchPaths;
     // search in the projects, as they're packages and likely to be installed or added to PYTHONPATH later
@@ -435,19 +445,20 @@
         searchPaths << Helper::projectSearchPaths;
         searchPaths << Helper::cachedCustomIncludes.value(project);
     }
-    
+
     foreach ( const QString& path, getDataDirs() ) {
         searchPaths.append(QUrl::fromLocalFile(path));
     }
 
     if ( !cachedSearchPaths.contains(project) ) {
+        auto runtime = ICore::self()->runtimeController()->currentRuntime();
         QVector<QUrl> cachedForProject;
         qCDebug(KDEV_PYTHON_DUCHAIN) << "*** Collecting search paths...";
-        QStringList getpath;
-        getpath << "-c" << "import sys; sys.stdout.write('$|$'.join(sys.path))";
-        
+
         QProcess python;
-        python.start(getPythonExecutablePath(project), getpath);
+        python.setProgram(getPythonExecutablePath(project));
+        python.setArguments({"-c", "import sys; sys.stdout.write('$|$'.join(sys.path))"});
+        runtime->startProcess(&python);
         python.waitForFinished(1000);
         QString pythonpath = QString::fromUtf8(python.readAllStandardOutput());
         auto paths = pythonpath.split("$|$");
@@ -460,12 +471,12 @@
         }
         else {
             qCWarning(KDEV_PYTHON_DUCHAIN) << "Could not get search paths! Defaulting to stupid stuff.";
-            searchPaths.append(QUrl::fromLocalFile("/usr/lib/python" PYTHON_VERSION_STR));
-            searchPaths.append(QUrl::fromLocalFile("/usr/lib/python" PYTHON_VERSION_STR "/site-packages"));
-            QString path = qgetenv("PYTHONPATH");
+            searchPaths.append(runtime->pathInHost(Path("/usr/lib/python" PYTHON_VERSION_STR)).toUrl());
+            searchPaths.append(runtime->pathInHost(Path("/usr/lib/python" PYTHON_VERSION_STR "/site-packages")).toUrl());
+            QString path = runtime->getenv("PYTHONPATH");
             QStringList paths = path.split(':');
             foreach ( const QString& path, paths ) {
-                cachedForProject.append(QUrl::fromLocalFile(path));
+                cachedForProject.append(runtime->pathInHost(Path(path)).toUrl());
             }
         }
         qCDebug(KDEV_PYTHON_DUCHAIN) << " *** Done. Got search paths: " << cachedSearchPaths;