diff --git a/base/remote_gdb.cc b/base/remote_gdb.cc
index 1f3a60bbf..67d745d43 100644
--- a/base/remote_gdb.cc
+++ b/base/remote_gdb.cc
@@ -133,7 +133,7 @@
 
 using namespace std;
 
-#ifdef DEBUG
+#ifndef NDEBUG
 vector<RemoteGDB *> debuggers;
 int current_debugger = -1;
 
@@ -195,12 +195,12 @@ GDBListener::listen()
     event = new Event(this, listener.getfd(), POLLIN);
     pollQueue.schedule(event);
 
-#ifdef DEBUG
+#ifndef NDEBUG
     gdb->number = debuggers.size();
     debuggers.push_back(gdb);
 #endif
 
-#ifdef DEBUG
+#ifndef NDEBUG
     ccprintf(cerr, "%d: %s: listening for remote gdb #%d on port %d\n",
              curTick, name(), gdb->number, port);
 #else
diff --git a/sim/system.cc b/sim/system.cc
index c91d7f142..4bcc89c56 100644
--- a/sim/system.cc
+++ b/sim/system.cc
@@ -123,7 +123,7 @@ System::System(Params *p)
     DPRINTF(Loader, "Kernel loaded...\n");
 
     Addr addr = 0;
-#ifdef DEBUG
+#ifndef NDEBUG
     consolePanicEvent = addConsoleFuncEvent<BreakPCEvent>("panic");
 #endif
 
diff --git a/sim/system.hh b/sim/system.hh
index 8cfe790de..aa697c040 100644
--- a/sim/system.hh
+++ b/sim/system.hh
@@ -97,7 +97,7 @@ class System : public SimObject
 
     Kernel::Binning *kernelBinning;
 
-#ifdef DEBUG
+#ifndef NDEBUG
     /** Event to halt the simulator if the console calls panic() */
     BreakPCEvent *consolePanicEvent;
 #endif