diff --git a/simulator/data_recorder.c b/simulator/data_recorder.c
index 7880675..f4ee399 100644
--- a/simulator/data_recorder.c
+++ b/simulator/data_recorder.c
@@ -30,8 +30,9 @@ static void recorder_close(void) {
 void recorder_init(const char* filename) {
   sim_assert( ! file, "Recorder already initialized");
 
+  sim_info("Opening recorder file %s.", filename);
   file = fopen(filename, "w");
-  sim_assert(file, "record_init: failed to create file");
+  sim_assert(file, "record_init: failed to create recorder file.");
 
   time_t t = time(NULL);
   fprintf(file, "# Teacup_Firmware simulator v1.0\n");
diff --git a/simulator/serial_sim.c b/simulator/serial_sim.c
index e63acb2..0a96c07 100644
--- a/simulator/serial_sim.c
+++ b/simulator/serial_sim.c
@@ -41,13 +41,13 @@ static void open_file() {
   // No more files
   if (i > g_argc) return;
 
-  sim_info("opening %s", filename);
-  sim_assert(!stat(filename, &st), "Could not stat file.");
+  sim_info("Opening G-code source %s.", filename);
+  sim_assert(!stat(filename, &st), "Could not stat G-code source.");
 
   if (!st.st_rdev) {
     // Normal file
     gcode_fd = open(filename, O_RDONLY );
-    sim_assert(gcode_fd, "Could not open file.");
+    sim_assert(gcode_fd, "Could not open G-code file.");
   } else {
     // Some kind of device (treat as TTY)
     open_tty(filename);