diff --git a/src/logger.c b/src/logger.c
index d09220e..3f49528 100644
--- a/src/logger.c
+++ b/src/logger.c
@@ -115,8 +115,6 @@ int main (int argc, char *argv [])
       // Get power measurement timestamp:
       clock_gettime(CLOCK_REALTIME,&power_ts);
       char line[MAX_RECORD_LEN];
-      sprintf(line,"%ld,%ld,%d\n",power_ts.tv_sec,power_ts.tv_nsec,atoi(buffer));
-      int linelen=strlen(line);
       if((queues[queue_id].size+MAX_RECORD_LEN)>ZMQ_MSG_SIZE){
         printf("To many measurements to publish. Please increase ZMQ_MSG_SIZE\n");
       } else {
diff --git a/src/subscriber.c b/src/subscriber.c
index 1024041..9902d92 100644
--- a/src/subscriber.c
+++ b/src/subscriber.c
@@ -73,7 +73,11 @@ int main (int argc, char *argv [])
         }
         // Now open output file:
         sprintf(path,"%s/%s/%s/%ld",cdatadir,key,client,interval);
+        char exists=FILE_EXISTS(path);
         fptr=fopen(path,"a");
+        if(!exists){
+          fwrite(CSV_HEADER"\n", strlen(CSV_HEADER)+1, 1, fptr);
+        }
       }
 
       // Write all the measurements:
diff --git a/src/utils.h b/src/utils.h
index 2f5f82a..5cf2b3c 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -12,6 +12,7 @@
 #define STATIC_LEN 255
 #define MAX_RECORD_LEN 100
 #define MAX_QUEUES 1
+#define CSV_HEADER "timestamp,nsecs,power"
 
 #ifndef ZMQ_TOKEN
 #define ZMQ_TOKEN "ina260-zmq-publisher"