diff --git a/launcher/launch/LaunchTask.cpp b/launcher/launch/LaunchTask.cpp
index 06a32bd28..0e23031f5 100644
--- a/launcher/launch/LaunchTask.cpp
+++ b/launcher/launch/LaunchTask.cpp
@@ -44,7 +44,6 @@
 #include <QRegularExpression>
 #include <QStandardPaths>
 #include "MessageLevel.h"
-#include "java/JavaChecker.h"
 #include "tasks/Task.h"
 
 void LaunchTask::init()
@@ -255,20 +254,60 @@ void LaunchTask::emitFailed(QString reason)
     Task::emitFailed(reason);
 }
 
-void LaunchTask::substituteVariables(QStringList& args) const
+QString expandVariables(const QString& input, QProcessEnvironment dict)
 {
-    auto env = m_instance->createEnvironment();
+    QString result = input;
 
-    for (auto key : env.keys()) {
-        args.replaceInStrings("$" + key, env.value(key));
+    enum { base, maybeBrace, variable, brace } state = base;
+    int startIdx = -1;
+    for (int i = 0; i < result.length();) {
+        QChar c = result.at(i++);
+        switch (state) {
+            case base:
+                if (c == '$')
+                    state = maybeBrace;
+                break;
+            case maybeBrace:
+                if (c == '{') {
+                    state = brace;
+                    startIdx = i;
+                } else if (c.isLetterOrNumber() || c == '_') {
+                    state = variable;
+                    startIdx = i - 1;
+                } else {
+                    state = base;
+                }
+                break;
+            case brace:
+                if (c == '}') {
+                    const auto res = dict.value(result.mid(startIdx, i - 1 - startIdx), "");
+                    if (!res.isEmpty()) {
+                        result.replace(startIdx - 2, i - startIdx + 2, res);
+                        i = startIdx - 2 + res.length();
+                    }
+                    state = base;
+                }
+                break;
+            case variable:
+                if (!c.isLetterOrNumber() && c != '_') {
+                    const auto res = dict.value(result.mid(startIdx, i - startIdx - 1), "");
+                    if (!res.isEmpty()) {
+                        result.replace(startIdx - 1, i - startIdx, res);
+                        i = startIdx - 1 + res.length();
+                    }
+                    state = base;
+                }
+                break;
+        }
     }
+    if (state == variable) {
+        if (const auto res = dict.value(result.mid(startIdx), ""); !res.isEmpty())
+            result.replace(startIdx - 1, result.length() - startIdx + 1, res);
+    }
+    return result;
 }
 
-void LaunchTask::substituteVariables(QString& cmd) const
+QString LaunchTask::substituteVariables(QString& cmd) const
 {
-    auto env = m_instance->createEnvironment();
-
-    for (auto key : env.keys()) {
-        cmd.replace("$" + key, env.value(key));
-    }
-}
+    return expandVariables(cmd, m_instance->createEnvironment());
+}
\ No newline at end of file
diff --git a/launcher/launch/LaunchTask.h b/launcher/launch/LaunchTask.h
index e79c43557..e9c2c373f 100644
--- a/launcher/launch/LaunchTask.h
+++ b/launcher/launch/LaunchTask.h
@@ -87,8 +87,7 @@ class LaunchTask : public Task {
     shared_qobject_ptr<LogModel> getLogModel();
 
    public:
-    void substituteVariables(QStringList& args) const;
-    void substituteVariables(QString& cmd) const;
+    QString substituteVariables(QString& cmd) const;
     QString censorPrivateInfo(QString in);
 
    protected: /* methods */
diff --git a/launcher/launch/steps/PostLaunchCommand.cpp b/launcher/launch/steps/PostLaunchCommand.cpp
index 725101224..946560c10 100644
--- a/launcher/launch/steps/PostLaunchCommand.cpp
+++ b/launcher/launch/steps/PostLaunchCommand.cpp
@@ -47,19 +47,15 @@ PostLaunchCommand::PostLaunchCommand(LaunchTask* parent) : LaunchStep(parent)
 
 void PostLaunchCommand::executeTask()
 {
-    // FIXME: where to put this?
+    auto cmd = m_parent->substituteVariables(m_command);
+    emit logLine(tr("Running Post-Launch command: %1").arg(cmd), MessageLevel::Launcher);
 #if QT_VERSION >= QT_VERSION_CHECK(5, 15, 0)
-    auto args = QProcess::splitCommand(m_command);
-    m_parent->substituteVariables(args);
+    auto args = QProcess::splitCommand(cmd);
 
-    emit logLine(tr("Running Post-Launch command: %1").arg(args.join(' ')), MessageLevel::Launcher);
     const QString program = args.takeFirst();
     m_process.start(program, args);
 #else
-    m_parent->substituteVariables(m_command);
-
-    emit logLine(tr("Running Post-Launch command: %1").arg(m_command), MessageLevel::Launcher);
-    m_process.start(m_command);
+    m_process.start(cmd);
 #endif
 }
 
diff --git a/launcher/launch/steps/PreLaunchCommand.cpp b/launcher/launch/steps/PreLaunchCommand.cpp
index 6d071a66e..3505febf7 100644
--- a/launcher/launch/steps/PreLaunchCommand.cpp
+++ b/launcher/launch/steps/PreLaunchCommand.cpp
@@ -47,19 +47,14 @@ PreLaunchCommand::PreLaunchCommand(LaunchTask* parent) : LaunchStep(parent)
 
 void PreLaunchCommand::executeTask()
 {
-    // FIXME: where to put this?
+    auto cmd = m_parent->substituteVariables(m_command);
+    emit logLine(tr("Running Pre-Launch command: %1").arg(cmd), MessageLevel::Launcher);
 #if QT_VERSION >= QT_VERSION_CHECK(5, 15, 0)
-    auto args = QProcess::splitCommand(m_command);
-    m_parent->substituteVariables(args);
-
-    emit logLine(tr("Running Pre-Launch command: %1").arg(args.join(' ')), MessageLevel::Launcher);
+    auto args = QProcess::splitCommand(cmd);
     const QString program = args.takeFirst();
     m_process.start(program, args);
 #else
-    m_parent->substituteVariables(m_command);
-
-    emit logLine(tr("Running Pre-Launch command: %1").arg(m_command), MessageLevel::Launcher);
-    m_process.start(m_command);
+    m_process.start(cmd);
 #endif
 }