diff --git a/grobid-home/pdfalto/lin-64/pdfalto_server b/grobid-home/pdfalto/lin-64/pdfalto_server
index 07a99f220a..db8d9f15bd 100755
--- a/grobid-home/pdfalto/lin-64/pdfalto_server
+++ b/grobid-home/pdfalto/lin-64/pdfalto_server
@@ -6,7 +6,7 @@ timeout=20   # 20 seconds
 interval=1
 # Delay between posting the SIGTERM signal and destroying the process by SIGKILL.
 delay=0
-# Limit the memory usage by this bash script
+# Default limit for the memory usage by this bash script
 memory_limit=6242304
 
 command=${0:0:${#0}-7}
diff --git a/grobid-home/pdfalto/mac-64/pdfalto_server b/grobid-home/pdfalto/mac-64/pdfalto_server
index 07f1b001cb..8fa2fafa78 100755
--- a/grobid-home/pdfalto/mac-64/pdfalto_server
+++ b/grobid-home/pdfalto/mac-64/pdfalto_server
@@ -6,8 +6,10 @@ timeout=20   # 20 seconds
 interval=1
 # Delay between posting the SIGTERM signal and destroying the process by SIGKILL.
 delay=0
-command=${0:0:${#0}-7}
+# Default limit for the memory usage by this bash script
+memory_limit=6242304
 
+command=${0:0:${#0}-7}
 args=("$@")
 pdfalto_params=()
 
@@ -17,12 +19,19 @@ for ((n=0; n<="$#";n++)); do
 	        timeout=${args[n+1]}
             ((n++))
             ;;
+         --ulimit) 
+          memory_limit=${args[n+1]}
+              ((n++))
+              ;;
          *)
             pdfalto_params+=" ${args[n]}"
             ;;
    esac
 done
 
+# Limit the memory usage by this bash script
+ulimit -Sv $memory_limit
+
 # kill -0 pid   Exit code indicates if a signal may be sent to $pid process.
 (
     ((t = timeout))