diff --git a/plugins/bind/bind9_resolver_stats b/plugins/bind/bind9_resolver_stats
index 86e410d5..80f20373 100755
--- a/plugins/bind/bind9_resolver_stats
+++ b/plugins/bind/bind9_resolver_stats
@@ -72,9 +72,7 @@ if [ "$1" = "config" ]; then
 
 	# If dirty config capability is enabled then fall through
 	# to output the data with the config information.
-	if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-		exit 0
-	fi
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 # Output the stats.
diff --git a/plugins/bind/bind9_server_stats b/plugins/bind/bind9_server_stats
index 4d495982..3c211e3c 100755
--- a/plugins/bind/bind9_server_stats
+++ b/plugins/bind/bind9_server_stats
@@ -69,11 +69,9 @@ if [ "$1" = "config" ]; then
 		echo ${key}.type COUNTER
 	done
 
-        # If dirty config capability is enabled then fall through
-        # to output the data with the config information.
-        if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-                exit 0
-        fi
+	# If dirty config capability is enabled then fall through
+	# to output the data with the config information.
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 # Output the stats.
diff --git a/plugins/bind/bind9_socket_stats b/plugins/bind/bind9_socket_stats
index be742f33..f84261ed 100755
--- a/plugins/bind/bind9_socket_stats
+++ b/plugins/bind/bind9_socket_stats
@@ -67,11 +67,9 @@ if [ "$1" = "config" ]; then
 		echo ${key}.type COUNTER
 	done
 
-        # If dirty config capability is enabled then fall through
-        # to output the data with the config information.
-        if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-                exit 0
-        fi
+	# If dirty config capability is enabled then fall through
+	# to output the data with the config information.
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 # Output the stats.
diff --git a/plugins/nginx/nginx_error b/plugins/nginx/nginx_error
index 9cb3d7df..6372867a 100755
--- a/plugins/nginx/nginx_error
+++ b/plugins/nginx/nginx_error
@@ -156,7 +156,7 @@ case ${1:-} in
   config)
     do_config
     # support "dirty config" capability
-    if [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ]; then do_fetch; fi
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then do_fetch; fi
     ;;
   autoconf)
     do_autoconf
diff --git a/plugins/oracle/oracle_sysstat b/plugins/oracle/oracle_sysstat
index 82159721..85ddd1f9 100755
--- a/plugins/oracle/oracle_sysstat
+++ b/plugins/oracle/oracle_sysstat
@@ -1119,7 +1119,7 @@ autoconf)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch
diff --git a/plugins/postgresql/pgbouncer_client_connections b/plugins/postgresql/pgbouncer_client_connections
index b179636e..0ba6e0ec 100755
--- a/plugins/postgresql/pgbouncer_client_connections
+++ b/plugins/postgresql/pgbouncer_client_connections
@@ -46,11 +46,9 @@ if [ "$1" = "config" ]; then
 	        echo ${pool}.type GAUGE
 	done
 
-        # If dirty config capability is enabled then fall through
-        # to output the data with the config information.
-        if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-                exit 0
-        fi
+	# If dirty config capability is enabled then fall through
+	# to output the data with the config information.
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 # Output looks like this:
diff --git a/plugins/postgresql/pgbouncer_maxwait b/plugins/postgresql/pgbouncer_maxwait
index bae7e8d8..a257ec6d 100755
--- a/plugins/postgresql/pgbouncer_maxwait
+++ b/plugins/postgresql/pgbouncer_maxwait
@@ -46,11 +46,9 @@ if [ "$1" = "config" ]; then
 	        echo ${pool}.type GAUGE
 	done
 
-        # If dirty config capability is enabled then fall through
-        # to output the data with the config information.
-        if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-                exit 0
-        fi
+	# If dirty config capability is enabled then fall through
+	# to output the data with the config information.
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 # Output looks like this:
diff --git a/plugins/postgresql/pgbouncer_server_connections b/plugins/postgresql/pgbouncer_server_connections
index ddd95964..6b63d2a9 100755
--- a/plugins/postgresql/pgbouncer_server_connections
+++ b/plugins/postgresql/pgbouncer_server_connections
@@ -46,11 +46,9 @@ if [ "$1" = "config" ]; then
 	        echo ${pool}.type GAUGE
 	done
 
-        # If dirty config capability is enabled then fall through
-        # to output the data with the config information.
-        if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-                exit 0
-        fi
+	# If dirty config capability is enabled then fall through
+	# to output the data with the config information.
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 # Output looks like this:
diff --git a/plugins/postgresql/postgresql_active_backends_by_database b/plugins/postgresql/postgresql_active_backends_by_database
index e4a53382..78a34745 100755
--- a/plugins/postgresql/postgresql_active_backends_by_database
+++ b/plugins/postgresql/postgresql_active_backends_by_database
@@ -73,9 +73,7 @@ if [ "$1" = "config" ]; then
 
 	# If dirty config capability is enabled then fall through
 	# to output the data with the config information.
-	if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-		exit 0
-	fi
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 while read pool sep backends junk
diff --git a/plugins/solaris/forks b/plugins/solaris/forks
index 5edf0a81..1744bdf3 100755
--- a/plugins/solaris/forks
+++ b/plugins/solaris/forks
@@ -98,7 +98,7 @@ autoconf)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch
diff --git a/plugins/solaris/fsstat_act_ b/plugins/solaris/fsstat_act_
index c9113586..3332e0a8 100755
--- a/plugins/solaris/fsstat_act_
+++ b/plugins/solaris/fsstat_act_
@@ -163,7 +163,7 @@ suggest)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch
diff --git a/plugins/solaris/fsstat_bytes b/plugins/solaris/fsstat_bytes
index c95bfdfc..4fb5e7e1 100755
--- a/plugins/solaris/fsstat_bytes
+++ b/plugins/solaris/fsstat_bytes
@@ -160,7 +160,7 @@ autoconf)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch
diff --git a/plugins/solaris/interrupts b/plugins/solaris/interrupts
index d421004e..7f1f49cc 100755
--- a/plugins/solaris/interrupts
+++ b/plugins/solaris/interrupts
@@ -118,7 +118,7 @@ autoconf)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch
diff --git a/plugins/solaris/io_disk b/plugins/solaris/io_disk
index 3701d16b..34ec68f0 100755
--- a/plugins/solaris/io_disk
+++ b/plugins/solaris/io_disk
@@ -334,7 +334,7 @@ autoconf)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch
diff --git a/plugins/streaming/packetship_ b/plugins/streaming/packetship_
index a9ec0964..b7465498 100755
--- a/plugins/streaming/packetship_
+++ b/plugins/streaming/packetship_
@@ -108,9 +108,7 @@ if [ "$1" = "config" ]; then
 
 	# If dirty config capability is enabled then fall through
 	# to output the data with the config information.
-	if [ "$MUNIN_CAP_DIRTYCONFIG" = "" ]; then
-		exit 0
-	fi
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" != "1" ]; then exit 0; fi
 fi
 
 # If there are no pumps then output fake pump1 data and end.
diff --git a/plugins/weather/openweather_ b/plugins/weather/openweather_
index ea232028..ffec4ea9 100755
--- a/plugins/weather/openweather_
+++ b/plugins/weather/openweather_
@@ -83,7 +83,7 @@ then
 	EOF
 
 	# Continue if dirty config is enabled
-	[ "$MUNIN_CAP_DIRTYCONFIG" = 1 ] || exit 0
+	[ "${MUNIN_CAP_DIRTYCONFIG:-0}" = 1 ] || exit 0
 fi
 
 TEMP_AVG=$( expr "$OWAPI" : '.*\<temperature value=\"\(.*\)\" min.*/temperature.*' )
diff --git a/plugins/wifi/wireless_channel_occupation_ b/plugins/wifi/wireless_channel_occupation_
index ebe6292d..20999b1c 100755
--- a/plugins/wifi/wireless_channel_occupation_
+++ b/plugins/wifi/wireless_channel_occupation_
@@ -135,7 +135,7 @@ elif [ "${1:-}" = "suggest" ]; then
 	done
 elif [ "${1:-}" = "config" ]; then
 	do_config || exit 1
-	[ "${MUNIN_CAP_DIRTYCONFIG:-0}" = 1 ] && do_fetch
+	if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then do_fetch; fi
 else
 	do_fetch
 fi
diff --git a/plugins/wifi/wireless_signal_noise_ b/plugins/wifi/wireless_signal_noise_
index 970399f1..c8761519 100755
--- a/plugins/wifi/wireless_signal_noise_
+++ b/plugins/wifi/wireless_signal_noise_
@@ -147,7 +147,7 @@ ACTION="${1:-}"
 case "$ACTION" in
 	config)
 		do_config || exit 1
-		[ "${MUNIN_CAP_DIRTYCONFIG:-0}" = 1 ] && do_fetch
+		if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then do_fetch; fi
 		;;
 	autoconf)
 		if [ -z "$(get_wifi_interfaces)" ]; then
diff --git a/plugins/wifi/wireless_signal_ranges_ b/plugins/wifi/wireless_signal_ranges_
index f17029c6..2f893970 100755
--- a/plugins/wifi/wireless_signal_ranges_
+++ b/plugins/wifi/wireless_signal_ranges_
@@ -138,7 +138,7 @@ ACTION="${1:-}"
 case "$ACTION" in
 	config)
 		do_config || exit 1
-		[ "${MUNIN_CAP_DIRTYCONFIG:-0}" = 1 ] && do_fetch
+		if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then do_fetch; fi
 		;;
 	autoconf)
 		[ -z "$(get_wifi_interfaces)" ] && echo "no (no wifi interfaces found)" && exit 1
diff --git a/plugins/zfs/zfs_arcstats b/plugins/zfs/zfs_arcstats
index 9dfebbad..7b0d74eb 100755
--- a/plugins/zfs/zfs_arcstats
+++ b/plugins/zfs/zfs_arcstats
@@ -351,7 +351,7 @@ autoconf)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch
diff --git a/plugins/zfs/zpool_capacity b/plugins/zfs/zpool_capacity
index 70411ae7..e8c7a3ce 100755
--- a/plugins/zfs/zpool_capacity
+++ b/plugins/zfs/zpool_capacity
@@ -257,7 +257,7 @@ autoconf)
     ;;
 config)
     config
-    [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ] && fetch
+    if [ "${MUNIN_CAP_DIRTYCONFIG:-0}" = "1" ]; then fetch; fi
     ;;
 *)
     fetch
diff --git a/plugins/znc/znc_logs.py b/plugins/znc/znc_logs.py
index c2812e4a..75a9671b 100755
--- a/plugins/znc/znc_logs.py
+++ b/plugins/znc/znc_logs.py
@@ -159,7 +159,7 @@ def emit_config():
     print('graph_period minute')
     graph_order = []
 
-    if 'MUNIN_CAP_DIRTYCONFIG' in os.environ and os.environ['MUNIN_CAP_DIRTYCONFIG'] == 1:
+    if os.getenv('MUNIN_CAP_DIRTYCONFIG') == "1":
         read_data(1)
     else:
         read_data(0)