diff --git a/test/falco_test.py b/test/falco_test.py
index 1e0da0d6..4a5e5ed0 100644
--- a/test/falco_test.py
+++ b/test/falco_test.py
@@ -650,7 +650,7 @@ class FalcoTest(Test):
         if self.time_iso_8601:
             cmd += ' -o time_format_iso_8601=true'
 
-        self.falco_proc = process.SubProcess(cmd)
+        self.falco_proc = process.SubProcess(cmd, env=dict(os.environ, FALCO_HOSTNAME="test-falco-hostname"))
 
         res = self.falco_proc.run(timeout=180, sig=9)
 
diff --git a/test/output_files/single_rule_with_cat_write.json b/test/output_files/single_rule_with_cat_write.json
index a430188b..ad3675bf 100644
--- a/test/output_files/single_rule_with_cat_write.json
+++ b/test/output_files/single_rule_with_cat_write.json
@@ -1,8 +1,8 @@
-{"output":"2016-08-04T16:17:57.881781397+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.881781397Z", "output_fields": {"evt.time.iso8601":1470327477881781397,"proc.cmdline":"cat /dev/null"}}
-{"output":"2016-08-04T16:17:57.881785348+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.881785348Z", "output_fields": {"evt.time.iso8601":1470327477881785348,"proc.cmdline":"cat /dev/null"}}
-{"output":"2016-08-04T16:17:57.881796705+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.881796705Z", "output_fields": {"evt.time.iso8601":1470327477881796705,"proc.cmdline":"cat /dev/null"}}
-{"output":"2016-08-04T16:17:57.881799840+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.881799840Z", "output_fields": {"evt.time.iso8601":1470327477881799840,"proc.cmdline":"cat /dev/null"}}
-{"output":"2016-08-04T16:17:57.882003104+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.882003104Z", "output_fields": {"evt.time.iso8601":1470327477882003104,"proc.cmdline":"cat /dev/null"}}
-{"output":"2016-08-04T16:17:57.882008208+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.882008208Z", "output_fields": {"evt.time.iso8601":1470327477882008208,"proc.cmdline":"cat /dev/null"}}
-{"output":"2016-08-04T16:17:57.882045694+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.882045694Z", "output_fields": {"evt.time.iso8601":1470327477882045694,"proc.cmdline":"cat /dev/null"}}
-{"output":"2016-08-04T16:17:57.882054739+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.882054739Z", "output_fields": {"evt.time.iso8601":1470327477882054739,"proc.cmdline":"cat /dev/null"}}
+{"hostname":"test-falco-hostname","output":"2016-08-04T16:17:57.881781397+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.881781397Z", "output_fields": {"evt.time.iso8601":1470327477881781397,"proc.cmdline":"cat /dev/null"}}
+{"hostname":"test-falco-hostname","output":"2016-08-04T16:17:57.881785348+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.881785348Z", "output_fields": {"evt.time.iso8601":1470327477881785348,"proc.cmdline":"cat /dev/null"}}
+{"hostname":"test-falco-hostname","output":"2016-08-04T16:17:57.881796705+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.881796705Z", "output_fields": {"evt.time.iso8601":1470327477881796705,"proc.cmdline":"cat /dev/null"}}
+{"hostname":"test-falco-hostname","output":"2016-08-04T16:17:57.881799840+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.881799840Z", "output_fields": {"evt.time.iso8601":1470327477881799840,"proc.cmdline":"cat /dev/null"}}
+{"hostname":"test-falco-hostname","output":"2016-08-04T16:17:57.882003104+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.882003104Z", "output_fields": {"evt.time.iso8601":1470327477882003104,"proc.cmdline":"cat /dev/null"}}
+{"hostname":"test-falco-hostname","output":"2016-08-04T16:17:57.882008208+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.882008208Z", "output_fields": {"evt.time.iso8601":1470327477882008208,"proc.cmdline":"cat /dev/null"}}
+{"hostname":"test-falco-hostname","output":"2016-08-04T16:17:57.882045694+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.882045694Z", "output_fields": {"evt.time.iso8601":1470327477882045694,"proc.cmdline":"cat /dev/null"}}
+{"hostname":"test-falco-hostname","output":"2016-08-04T16:17:57.882054739+0000: Warning An open was seen (command=cat /dev/null)","priority":"Warning","rule":"open_from_cat","source":"syscall","tags":["filesystem","process","testing"],"time":"2016-08-04T16:17:57.882054739Z", "output_fields": {"evt.time.iso8601":1470327477882054739,"proc.cmdline":"cat /dev/null"}}