diff --git a/nix/debugger.cpp b/nix/debugger.cpp
index 31e2e67..494f5b9 100644
--- a/nix/debugger.cpp
+++ b/nix/debugger.cpp
@@ -73,13 +73,13 @@ Debugger::Debugger()
 
 Debugger::~Debugger()
 {
-  struct _history *h = history;
-  while (h) {
+  while (history) {
     struct _history *n = history->next;
-    free(h->msg);
-    delete(h);
-    h = n;
+    free(history->msg);
+    delete(history);
+    history = n;
   }
+  history = NULL;
 }
 
 bool getAddress(const char *buf, unsigned int *addrOut)
diff --git a/sdl/aiie.cpp b/sdl/aiie.cpp
index 34002a1..4b66a80 100644
--- a/sdl/aiie.cpp
+++ b/sdl/aiie.cpp
@@ -160,14 +160,21 @@ static struct timespec runCPU(struct timespec now)
 
   // Run the CPU
   uint8_t executed = 0;
+  bool debuggerWasActive = false;
   if (debugger.active()) {
     // With the debugger running, we need to single-step through
     // instructions.
     executed = g_cpu->Run(1);
+    debuggerWasActive = true;
   } else {
     // Otherwise we can run a bunch of instructions at once to
     // save on the overhead.
     executed = g_cpu->Run(24);
+    if (debuggerWasActive) {
+      cpuClockInitialized = false;
+      g_cpu->cycles = 0;
+      debuggerWasActive = false;
+    }
   }
 
   // The paddles need to be triggered in real-time on the CPU
@@ -176,9 +183,6 @@ static struct timespec runCPU(struct timespec now)
   
   if (debugger.active()) {
     debugger.step();
-    // reset time flags
-    cpuClockInitialized = false;
-    g_cpu->cycles = 0;
   }
   
   if (send_rst) {