diff --git a/cgi-bin/searchapi.cgi b/cgi-bin/searchapi.cgi
index 3f6fce7..6587970 100755
--- a/cgi-bin/searchapi.cgi
+++ b/cgi-bin/searchapi.cgi
@@ -75,8 +75,8 @@ else
   # Adjust 'QS_q' for the locate command by wrapping search elements in *.
   QS_q="*${QS_q// /* *}*"
 
-  # Adjust 'QS_l' to not go over maximum limit of results, or use default if not supplied.
-  [[ -z "$QS_l" ]] && QS_l="$DEF_RESULTS"
+  # Adjust 'QS_l' to not go over maximum limit of results, or use default if not supplied or invalid.
+  [[ -z "$QS_l" ]] || [[ ! "$QS_l" =~ ^[[:digit:]]+$ ]] && QS_l="$DEF_RESULTS"
   (( QS_l > MAX_RESULTS )) && QS_l="$MAX_RESULTS"
 
   # Give success status as checks have passed.