diff --git a/polymer/eduke32/build/src/util/checkdefs.sh b/polymer/eduke32/build/src/util/checkdefs.sh
index a6d9fc416..eb4490244 100755
--- a/polymer/eduke32/build/src/util/checkdefs.sh
+++ b/polymer/eduke32/build/src/util/checkdefs.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 
 if [ -z "$1" ]; then
-    echo 'Usage: checkdefs.sh <some.def> [[<some_dir>] -patch]'
+    echo 'Usage: checkdefs.sh <some.def> [[<some_dir>] {-patch,-con,-conpatch}]'
     exit 1
 fi
 deffn="$1"
@@ -12,14 +12,30 @@ else
     thedir="$2"
 fi
 
+dopatch=""
+docon=""
 if [ -n "$3" ]; then
-    if [ "$3" != "-patch" ]; then
-        echo 'Usage: checkdefs.sh <some.def> [[<some_dir>] -patch]'
+    if [ "$3" != "-patch" -a "$3" != "-con" -a "$3" != "-conpatch" ]; then
+        echo 'Usage: checkdefs.sh <some.def> [[<some_dir>] {-patch,-con,-conpatch}]'
         exit 1
     fi
+    if [ "$3" == "-patch" ]; then
+        dopatch=1
+    elif [ "$3" == "-con" ]; then
+        docon=1
+    else
+        docon=1
+        dopatch=1
+    fi
 fi
 
-files=$(grep -E "\".*\..*\"" "$deffn" | sed 's/.*"\(.*\..*\)".*/\1/g')
+if [ -z $docon ]; then
+    # def
+    files=$(grep -E "\".*\..*\"" "$deffn" | sed 's/.*"\(.*\..*\)".*/\1/g')
+else
+    # con... this is awful
+    files=$(grep -E -i '(include *.*\.con)|(definesound.*(voc|wav|ogg))' "$deffn" | sed -r 's/.*include[ \t]+([^ \t]+\.[cC][oO][nN]).*/\1/g; s/.*[ \t]([^ \t].+\.([wW][aA][vV]|[vV][oO][cC]|[oO][gG][gG])).*/\1/g')
+fi
 
 exfiles=$(find "$thedir" -type f)
 
@@ -32,15 +48,23 @@ for i in $files; do
         match=$(echo "$exfiles" | grep -i "^$fn$")
 
         if [ -z "$match" ]; then
-            echo "$fn"
+            if [ -z "$docon" ]; then  # avoid spamming files not found that are in GRPs...
+                echo "$fn"
+            fi
         else
             echo "$fn --> $match"
-            sedcmd="$sedcmd;s|\"$i\"|\"${match#$thedir/}\"|g"
+            if [ -n "$dopatch" ]; then
+                if [ -z "$docon" ]; then
+                    sedcmd="$sedcmd;s|\"$i\"|\"${match#$thedir/}\"|g"
+                else
+                    sedcmd="$sedcmd;s|$i|${match#$thedir/}|g"
+                fi
+            fi
         fi
     fi
 done
 
-if [ -n "$3" ]; then
+if [ -n "$dopatch" ]; then
     if [ -n "$sedcmd" ]; then
         echo "Patching $deffn"
 #        echo "$sedcmd"