diff --git a/wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/ParallelDeadlineGroup.java b/wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/ParallelDeadlineGroup.java
index 61517ef140..37be7025a8 100644
--- a/wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/ParallelDeadlineGroup.java
+++ b/wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/ParallelDeadlineGroup.java
@@ -21,6 +21,7 @@ public class ParallelDeadlineGroup extends CommandGroupBase {
   //maps commands in this group to whether they are still running
   private final Map<Command, Boolean> m_commands = new HashMap<>();
   private boolean m_runWhenDisabled = true;
+  private boolean m_finished = true;
   private Command m_deadline;
 
   /**
@@ -57,7 +58,7 @@ public class ParallelDeadlineGroup extends CommandGroupBase {
   public final void addCommands(Command... commands) {
     requireUngrouped(commands);
 
-    if (m_commands.containsValue(true)) {
+    if (!m_finished) {
       throw new IllegalStateException(
           "Commands cannot be added to a CommandGroup while the group is running");
     }
@@ -81,6 +82,7 @@ public class ParallelDeadlineGroup extends CommandGroupBase {
       commandRunning.getKey().initialize();
       commandRunning.setValue(true);
     }
+    m_finished = false;
   }
 
   @Override
@@ -93,6 +95,9 @@ public class ParallelDeadlineGroup extends CommandGroupBase {
       if (commandRunning.getKey().isFinished()) {
         commandRunning.getKey().end(false);
         commandRunning.setValue(false);
+        if (commandRunning.getKey() == m_deadline) {
+          m_finished = true;
+        }
       }
     }
   }
@@ -108,7 +113,7 @@ public class ParallelDeadlineGroup extends CommandGroupBase {
 
   @Override
   public boolean isFinished() {
-    return m_deadline.isFinished();
+    return m_finished;
   }
 
   @Override
diff --git a/wpilibNewCommands/src/main/native/cpp/frc2/command/ParallelDeadlineGroup.cpp b/wpilibNewCommands/src/main/native/cpp/frc2/command/ParallelDeadlineGroup.cpp
index 910bc8ce1a..935cf8ba3d 100644
--- a/wpilibNewCommands/src/main/native/cpp/frc2/command/ParallelDeadlineGroup.cpp
+++ b/wpilibNewCommands/src/main/native/cpp/frc2/command/ParallelDeadlineGroup.cpp
@@ -21,7 +21,7 @@ void ParallelDeadlineGroup::Initialize() {
     commandRunning.first->Initialize();
     commandRunning.second = true;
   }
-  isRunning = true;
+  m_finished = false;
 }
 
 void ParallelDeadlineGroup::Execute() {
@@ -31,6 +31,9 @@ void ParallelDeadlineGroup::Execute() {
     if (commandRunning.first->IsFinished()) {
       commandRunning.first->End(false);
       commandRunning.second = false;
+      if (commandRunning.first.get() == m_deadline) {
+        m_finished = true;
+      }
     }
   }
 }
@@ -41,10 +44,9 @@ void ParallelDeadlineGroup::End(bool interrupted) {
       commandRunning.first->End(true);
     }
   }
-  isRunning = false;
 }
 
-bool ParallelDeadlineGroup::IsFinished() { return m_deadline->IsFinished(); }
+bool ParallelDeadlineGroup::IsFinished() { return m_finished; }
 
 bool ParallelDeadlineGroup::RunsWhenDisabled() const {
   return m_runWhenDisabled;
@@ -56,7 +58,7 @@ void ParallelDeadlineGroup::AddCommands(
     return;
   }
 
-  if (isRunning) {
+  if (!m_finished) {
     wpi_setWPIErrorWithContext(CommandIllegalUse,
                                "Commands cannot be added to a CommandGroup "
                                "while the group is running");
diff --git a/wpilibNewCommands/src/main/native/include/frc2/command/ParallelDeadlineGroup.h b/wpilibNewCommands/src/main/native/include/frc2/command/ParallelDeadlineGroup.h
index 1606548475..4debe75d74 100644
--- a/wpilibNewCommands/src/main/native/include/frc2/command/ParallelDeadlineGroup.h
+++ b/wpilibNewCommands/src/main/native/include/frc2/command/ParallelDeadlineGroup.h
@@ -101,7 +101,7 @@ class ParallelDeadlineGroup
   std::vector<std::pair<std::unique_ptr<Command>, bool>> m_commands;
   Command* m_deadline;
   bool m_runWhenDisabled{true};
-  bool isRunning = false;
+  bool m_finished{true};
 };
 }  // namespace frc2