diff --git a/src/plugins/debugger/debuggerengine.cpp b/src/plugins/debugger/debuggerengine.cpp
index 58f2ae00540..1436c45d07c 100644
--- a/src/plugins/debugger/debuggerengine.cpp
+++ b/src/plugins/debugger/debuggerengine.cpp
@@ -65,6 +65,7 @@
 #include <utils/macroexpander.h>
 #include <utils/processhandle.h>
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 #include <utils/savedaction.h>
 
 #include <QDebug>
@@ -1360,6 +1361,30 @@ QString DebuggerEngine::nativeStartupCommands() const
                                runParameters().additionalStartupCommands}).join('\n'));
 }
 
+bool DebuggerEngine::prepareCommand()
+{
+    if (HostOsInfo::isWindowsHost()) {
+        DebuggerRunParameters &rp = runParameters();
+        QtcProcess::SplitError perr;
+        rp.inferior.commandLineArguments =
+                QtcProcess::prepareArgs(rp.inferior.commandLineArguments, &perr,
+                                        HostOsInfo::hostOs(), nullptr,
+                                        &rp.inferior.workingDirectory).toWindowsArgs();
+        if (perr != QtcProcess::SplitOk) {
+            // perr == BadQuoting is never returned on Windows
+            // FIXME? QTCREATORBUG-2809
+            showMessage("ADAPTER START FAILED");
+            const QString title = tr("Adapter start failed");
+            const QString msg = tr("Debugging complex command lines "
+                                   "is currently not supported on Windows.");
+            ICore::showWarningWithOptions(title, msg);
+            notifyEngineSetupFailed();
+            return false;
+        }
+    }
+    return true;
+}
+
 void DebuggerEngine::updateBreakpointMarker(const Breakpoint &bp)
 {
     d->m_disassemblerAgent.updateBreakpointMarker(bp);
diff --git a/src/plugins/debugger/debuggerengine.h b/src/plugins/debugger/debuggerengine.h
index f25740b3170..88ab9dc2d27 100644
--- a/src/plugins/debugger/debuggerengine.h
+++ b/src/plugins/debugger/debuggerengine.h
@@ -338,6 +338,8 @@ public:
     QString expand(const QString &string) const;
     QString nativeStartupCommands() const;
 
+    bool prepareCommand();
+
 signals:
     void stateChanged(Debugger::DebuggerState state);
     /*
diff --git a/src/plugins/debugger/gdb/gdbengine.cpp b/src/plugins/debugger/gdb/gdbengine.cpp
index db71ce6ecc1..9bbbda7dd36 100644
--- a/src/plugins/debugger/gdb/gdbengine.cpp
+++ b/src/plugins/debugger/gdb/gdbengine.cpp
@@ -4300,26 +4300,6 @@ void GdbEngine::requestDebugInformation(const DebugInfoTask &task)
     QProcess::startDetached(task.command);
 }
 
-bool GdbEngine::prepareCommand()
-{
-    if (HostOsInfo::isWindowsHost()) {
-        DebuggerRunParameters &rp = runParameters();
-        QtcProcess::SplitError perr;
-        rp.inferior.commandLineArguments =
-                QtcProcess::prepareArgs(rp.inferior.commandLineArguments, &perr,
-                                        HostOsInfo::hostOs(), nullptr,
-                                        &rp.inferior.workingDirectory).toWindowsArgs();
-        if (perr != QtcProcess::SplitOk) {
-            // perr == BadQuoting is never returned on Windows
-            // FIXME? QTCREATORBUG-2809
-            handleAdapterStartFailed(QCoreApplication::translate("DebuggerEngine", // Same message in CdbEngine
-                                                                 "Debugging complex command lines is currently not supported on Windows."), Id());
-            return false;
-        }
-    }
-    return true;
-}
-
 QString GdbEngine::msgGdbStopFailed(const QString &why)
 {
     return tr("The gdb process could not be stopped:\n%1").arg(why);
diff --git a/src/plugins/debugger/gdb/gdbengine.h b/src/plugins/debugger/gdb/gdbengine.h
index 169bef5aba2..45b99ec398d 100644
--- a/src/plugins/debugger/gdb/gdbengine.h
+++ b/src/plugins/debugger/gdb/gdbengine.h
@@ -418,7 +418,6 @@ protected:
     DebuggerCommand m_lastDebuggableCommand;
 
 protected:
-    bool prepareCommand();
     void interruptLocalInferior(qint64 pid);
 
 protected:
diff --git a/src/plugins/debugger/lldb/lldbengine.cpp b/src/plugins/debugger/lldb/lldbengine.cpp
index c94a31d5a92..24bad856adc 100644
--- a/src/plugins/debugger/lldb/lldbengine.cpp
+++ b/src/plugins/debugger/lldb/lldbengine.cpp
@@ -176,25 +176,6 @@ void LldbEngine::abortDebugger()
     }
 }
 
-// FIXME: Merge with GdbEngine/QtcProcess
-bool LldbEngine::prepareCommand()
-{
-    if (HostOsInfo::isWindowsHost()) {
-        DebuggerRunParameters &rp = runParameters();
-        QtcProcess::SplitError perr;
-        rp.inferior.commandLineArguments
-                = QtcProcess::prepareArgs(rp.inferior.commandLineArguments, &perr, HostOsInfo::hostOs(),
-                                          nullptr, &rp.inferior.workingDirectory).toWindowsArgs();
-        if (perr != QtcProcess::SplitOk) {
-            // perr == BadQuoting is never returned on Windows
-            // FIXME? QTCREATORBUG-2809
-            notifyEngineSetupFailed();
-            return false;
-        }
-    }
-    return true;
-}
-
 void LldbEngine::setupEngine()
 {
     // FIXME: We can't handle terminals yet.
@@ -226,10 +207,8 @@ void LldbEngine::setupEngine()
     //    m_stubProc.stop();
     //    m_stubProc.blockSignals(false);
 
-        if (!prepareCommand()) {
-            notifyEngineSetupFailed();
+        if (!prepareCommand())
             return;
-        }
 
         m_stubProc.setWorkingDirectory(runParameters().inferior.workingDirectory);
         // Set environment + dumper preload.
diff --git a/src/plugins/debugger/lldb/lldbengine.h b/src/plugins/debugger/lldb/lldbengine.h
index eb653b48a5b..2b5d7b0b619 100644
--- a/src/plugins/debugger/lldb/lldbengine.h
+++ b/src/plugins/debugger/lldb/lldbengine.h
@@ -163,7 +163,6 @@ private:
     void stubError(const QString &msg);
     void stubExited();
     void stubStarted();
-    bool prepareCommand();
     Utils::ConsoleProcess m_stubProc;
 };