diff --git a/data/hd-rum-transcode.1 b/data/hd-rum-transcode.1
index 83dd87dc8..868913bba 100644
--- a/data/hd-rum-transcode.1
+++ b/data/hd-rum-transcode.1
@@ -2,12 +2,12 @@
 .\"     Title: hd-rum-transcode
 .\"    Author: [FIXME: author] [see http://www.docbook.org/tdg5/en/html/author]
 .\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
-.\"      Date: 03/29/2021
+.\"      Date: 05/26/2021
 .\"    Manual: \ \&
 .\"    Source: \ \&
 .\"  Language: English
 .\"
-.TH "HD\-RUM\-TRANSCODE" "1" "03/29/2021" "\ \&" "\ \&"
+.TH "HD\-RUM\-TRANSCODE" "1" "05/26/2021" "\ \&" "\ \&"
 .\" -----------------------------------------------------------------
 .\" * Define some portability stuff
 .\" -----------------------------------------------------------------
@@ -71,6 +71,15 @@ Transcoder can be used as a reflector also for audio (and must be used if audio
 .SS "Reflector running on UltraGrid sender machine"
 .sp
 \fBuv\fR \-t testcard \-s testcard \fI\-P 6004:5004:6006:5006\fR localhost \fBhd\-rum\-transcode\fR 8M 5004 receiver1 receiver2 \-c JPEG receiver3 # video \fBhd\-rum\-transcode\fR 8M 5006 receiver1 receiver2 receiver3 # audio
+.SH "ENVIRONMENT VARIABLES"
+.PP
+\fBULTRAGRID_VERBOSE\fR
+.RS 4
+If is
+ULTRAGRID_VERBOSE
+environment variable is set, default UltraGrid log level is
+verbose\&. Command\-line option always overrides this value\&.
+.RE
 .SH "REPORTING BUGS"
 .sp
 Report bugs to \fBultragrid\-dev@cesnet\&.cz\fR or use project \fBGitHub\fR to describe issues\&.
diff --git a/data/make_man.sh b/data/make_man.sh
index 399f9893d..c73be08c7 100755
--- a/data/make_man.sh
+++ b/data/make_man.sh
@@ -6,6 +6,11 @@
 
 bugreport_and_resources() {
 	cat <<-'EOF'
+	== ENVIRONMENT VARIABLES ==
+	*`ULTRAGRID_VERBOSE`*::
+	  If is `ULTRAGRID_VERBOSE` environment variable is set, default UltraGrid
+	  log level is `verbose`. Command-line option always overrides this value.
+
 	== REPORTING BUGS ==
 	Report bugs to *ultragrid-dev@cesnet.cz* or use project *GitHub* to describe issues.
 
diff --git a/data/uv.1 b/data/uv.1
index 1dab0c082..651743de0 100644
--- a/data/uv.1
+++ b/data/uv.1
@@ -2,12 +2,12 @@
 .\"     Title: uv
 .\"    Author: [FIXME: author] [see http://www.docbook.org/tdg5/en/html/author]
 .\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
-.\"      Date: 03/29/2021
+.\"      Date: 05/26/2021
 .\"    Manual: \ \&
 .\"    Source: \ \&
 .\"  Language: English
 .\"
-.TH "UV" "1" "03/29/2021" "\ \&" "\ \&"
+.TH "UV" "1" "05/26/2021" "\ \&" "\ \&"
 .\" -----------------------------------------------------------------
 .\" * Define some portability stuff
 .\" -----------------------------------------------------------------
@@ -421,6 +421,15 @@ address                         destination address
 .if n \{\
 .RE
 .\}
+.SH "ENVIRONMENT VARIABLES"
+.PP
+\fBULTRAGRID_VERBOSE\fR
+.RS 4
+If is
+ULTRAGRID_VERBOSE
+environment variable is set, default UltraGrid log level is
+verbose\&. Command\-line option always overrides this value\&.
+.RE
 .SH "REPORTING BUGS"
 .sp
 Report bugs to \fBultragrid\-dev@cesnet\&.cz\fR or use project \fBGitHub\fR to describe issues\&.
diff --git a/src/debug.cpp b/src/debug.cpp
index a2b19fbd0..be768bf34 100644
--- a/src/debug.cpp
+++ b/src/debug.cpp
@@ -234,6 +234,10 @@ bool set_log_level(const char *optarg, bool *logger_repeat_msgs) {
                 *logger_repeat_msgs = true;
         }
 
+        if (getenv("ULTRAGRID_VERBOSE") != nullptr) {
+                log_level = LOG_LEVEL_VERBOSE;
+        }
+
         if (optarg[0] == '+') {
                 return true;
         }