diff --git a/check_modules.sh b/check_modules.sh
index 90f31ec..18d3e1f 100755
--- a/check_modules.sh
+++ b/check_modules.sh
@@ -1,24 +1,46 @@
 #!/bin/bash -l
 #
-# Copyright (c) 2012-2015 Christoph Niethammer <niethammer@hlrs.de>
+# Copyright (c) 2012-2016 Christoph Niethammer <niethammer@hlrs.de>
 #
 # Script checking the module environment for problems during module loading/unloading
 #
-# Usage:
-# check_modules.sh [MODULE]
-#
-# Options:
-#   MODULE   May be any valid module path as used for 'module avail [MODULE]'
-#
+
+function print_usage() {
+    echo <<EOT
+Script checking the module environment for problems during module loading/unloading
+usage: $0 [MODULE_PATTERN] [--exclude PATTERN]"
+EOT 
+}
 
 # Command line options:
-moduleclass=$1  # check only subset of modules
+declare -a moduleclasses  # check only subset of modules
+declare -a exclude_pattern # exclude modules with given pattern, e.g. nightly builds
 
+while [[ $# -gt 0 ]]
+do
+    key="$1"
+    case $key in
+        --exclude-pattern|--exclude)
+            exclude_patterns+=($2)
+            shift 2
+        ;;
+        -h|--help)
+            print_usage
+            exit 0
+        ;;
+        *)
+            moduleclasses+=($1)
+            shift
+        ;;
+    esac
+done
 # definitions for esear color output to display
 Color_Off='\e[0m'       # Text Reset
 IGreen='\e[0;92m'       # Intense Green
 IRed='\e[0;91m'         # Intense Red
 
+            echo Moduleclasses: ${moduleclasses[@]}
+            echo Exclude: ${exclude_patterns[@]}
 # intermediate files, logfiles
 LOGDIR=${LOGDIR:=$PWD}
 tmpdir=/tmp/check_modules-$USER
@@ -48,60 +70,74 @@ echo "Environment:" >> $logfile
 cat $module_clean_env_file >> $logfile
 echo "--------------------" >> $logfile
 
-for m_original in $(module av -t $moduleclass 2>&1); do
-    if [[ $m_original =~ ^[A-Za-z] ]]; then # skip any non module line in output
-        m=$(echo $m_original | sed -e 's/(.*)//') # Remove aliases e.g. (default)
-        echo -n "Checking $m_original ... "
-        echo "Checking $m_original ... " >> $logfile
+for moduleclass in ${moduleclasses[@]}
+do
+    for m_original in $(module av -t $moduleclass 2>&1); do
+        match=0
+        for exclude_pattern in ${exclude_patterns[@]}
+        do
+            if [[ "$m_original" =~ "$exclude_pattern" ]]; then
+                echo MATCH: $exclude_pattern
+                match=1
+            fi
+        done
+        if [ $match == 1 ]; then
+            continue
+        fi
+        if [[ $m_original =~ ^[A-Za-z] ]]; then # skip any non module line in output
+            m=$(echo $m_original | sed -e 's/(.*)//') # Remove aliases e.g. (default)
+            echo -n "Checking $m_original ... "
+            echo "Checking $m_original ... " >> $logfile
 
-        cmd="module load $m"
-        echo $cmd >> $logfile
-        $cmd > $module_load_logfile 2>&1
-        cat $module_load_logfile >> $logfile
-        module li >>$logfile 2>&1
-
-        # check if module was loaded and did not report errors during loading
-        if  module li -t 2>&1 | grep $m >/dev/null &&  ! grep ERROR $module_load_logfile >/dev/null  ; then
-
-            cmd="module rm $m"
+            cmd="module load $m"
             echo $cmd >> $logfile
-            $cmd > $module_rm_logfile 2>&1
-            cat $module_rm_logfile >> $logfile
+            $cmd > $module_load_logfile 2>&1
+            cat $module_load_logfile >> $logfile
             module li >>$logfile 2>&1
 
-            # check if module was unloaded
-            if module li -t 2>&1 | grep $m > /dev/null; then
-                echo -e "${IRed}unloading failed${Color_Off}"
-                echo "ERROR: unloading module '$m' failed" >> $logfile
-                failed_modules=(${failed_modules[@]} $m_original)
+            # check if module was loaded and did not report errors during loading
+            if  module li -t 2>&1 | grep $m >/dev/null &&  ! grep ERROR $module_load_logfile >/dev/null  ; then
+
+                cmd="module rm $m"
+                echo $cmd >> $logfile
+                $cmd > $module_rm_logfile 2>&1
+                cat $module_rm_logfile >> $logfile
+                module li >>$logfile 2>&1
+
+                # check if module was unloaded
+                if module li -t 2>&1 | grep $m > /dev/null; then
+                    echo -e "${IRed}unloading failed${Color_Off}"
+                    echo "ERROR: unloading module '$m' failed" >> $logfile
+                    failed_modules=(${failed_modules[@]} $m_original)
+                else
+                    echo -e "${IGreen}success${Color_Off}"
+                    echo "SUCCESS" >> $logfile
+                fi
+
             else
-                echo -e "${IGreen}success${Color_Off}"
-                echo "SUCCESS" >> $logfile
+                echo -e "${IRed}loading failed${Color_Off}"
+                echo "ERROR: loading module '$m' failed" >> $logfile
+                failed_modules=(${failed_modules[@]} $m)
             fi
 
-        else
-            echo -e "${IRed}loading failed${Color_Off}"
-            echo "ERROR: loading module '$m' failed" >> $logfile
-            failed_modules=(${failed_modules[@]} $m)
+            # clean up module environment
+            cmd="module purge"
+            echo $cmd >> $logfile
+            $cmd >>$logfile 2>&1
+            module li >>$logfile 2>&1
+            echo "Resetting environment ..." >>$logfile
+
+            # Reset the complete environment manually to overcome problems with
+            # inconsistent internal caches of the module command after module purge.
+            source $module_clean_env_file 2>/dev/null
+
+            # clean up intermediate files
+            rm -f $module_load_logfile
+            rm -f $module_rm_logfile
+
+            echo >>$logfile 2>&1
         fi
-
-        # clean up module environment
-        cmd="module purge"
-        echo $cmd >> $logfile
-        $cmd >>$logfile 2>&1
-        module li >>$logfile 2>&1
-        echo "Resetting environment ..." >>$logfile
-
-        # Reset the complete environment manually to overcome problems with
-        # inconsistent internal caches of the module command after module purge.
-        source $module_clean_env_file 2>/dev/null
-
-        # clean up intermediate files
-        rm -f $module_load_logfile
-        rm -f $module_rm_logfile
-
-        echo >>$logfile 2>&1
-    fi
+    done
 done
 
 # clean up file storing the initial environment