diff --git a/app/models/ticket/number/date.rb b/app/models/ticket/number/date.rb
index a939e3297..244609cb7 100644
--- a/app/models/ticket/number/date.rb
+++ b/app/models/ticket/number/date.rb
@@ -86,12 +86,14 @@ module Ticket::Number::Date
     end
 
     # probe format
-    string.scan(/\b#{Regexp.quote(ticket_hook)}#{Regexp.quote(ticket_hook_divider)}(\d{4,10}#{system_id}\d{2,40})\b/i) do
+    # NOTE: we use `(?<=\W|^)` at the start of the regular expressions below
+    # because `\b` fails when ticket_hook begins with a non-word character (like '#')
+    string.scan(/(?<=\W|^)#{Regexp.quote(ticket_hook)}#{Regexp.quote(ticket_hook_divider)}(\d{4,10}#{system_id}\d{2,40})\b/i) do
       ticket = Ticket.find_by(number: $1)
       break if ticket
     end
     if !ticket
-      string.scan(/\b#{Regexp.quote(ticket_hook)}\s{0,2}(\d{4,10}#{system_id}\d{2,40})\b/i) do
+      string.scan(/(?<=\W|^)#{Regexp.quote(ticket_hook)}\s{0,2}(\d{4,10}#{system_id}\d{2,40})\b/i) do
         ticket = Ticket.find_by(number: $1)
         break if ticket
       end
diff --git a/app/models/ticket/number/increment.rb b/app/models/ticket/number/increment.rb
index adbc39281..d104f6ed1 100644
--- a/app/models/ticket/number/increment.rb
+++ b/app/models/ticket/number/increment.rb
@@ -83,12 +83,14 @@ module Ticket::Number::Increment
     end
 
     # probe format
-    string.scan(/\b#{Regexp.quote(ticket_hook)}#{Regexp.quote(ticket_hook_divider)}(#{system_id}\d{2,48})\b/i) do
+    # NOTE: we use `(?<=\W|^)` at the start of the regular expressions below
+    # because `\b` fails when ticket_hook begins with a non-word character (like '#')
+    string.scan(/(?<=\W|^)#{Regexp.quote(ticket_hook)}#{Regexp.quote(ticket_hook_divider)}(#{system_id}\d{2,48})\b/i) do
       ticket = Ticket.find_by(number: $1)
       break if ticket
     end
     if !ticket
-      string.scan(/\b#{Regexp.quote(ticket_hook)}\s{0,2}(#{system_id}\d{2,48})\b/i) do
+      string.scan(/(?<=\W|^)#{Regexp.quote(ticket_hook)}\s{0,2}(#{system_id}\d{2,48})\b/i) do
         ticket = Ticket.find_by(number: $1)
         break if ticket
       end