diff --git a/tools/pdbgen/pdbgen.pl b/tools/pdbgen/pdbgen.pl
index bf6dd85570..e1df743285 100755
--- a/tools/pdbgen/pdbgen.pl
+++ b/tools/pdbgen/pdbgen.pl
@@ -128,8 +128,8 @@ foreach $file (@groups) {
 # Squash whitespace into just single spaces between words.
 # Single new lines are considered as normal spaces, but n > 1 newlines are considered (n - 1) newlines.
 # The sligthly complicated suite of regexp is so that \n\s+\n is still considered a double newline.
-sub trimspace { for (${$_[0]}) { s/(\S)[\ \t\r\f]*\n[\ \t\r\f]*(\S)/\1 \2/g; s/[\ \t\r\f]+/ /gs;
-    s/\n(([\ \t\r\f]*\n)+)/\1/g; s/[\ \t\r\f]*\n[\ \t\r\f]/\n/g ; s/^\s+//; s/\s+$//; } }
+sub trimspace { for (${$_[0]}) { s/(\S)[\ \t\r\f]*\n[\ \t\r\f]*(\S)/$1 $2/g; s/[\ \t\r\f]+/ /gs;
+    s/\n(([\ \t\r\f]*\n)+)/$1/g; s/[\ \t\r\f]*\n[\ \t\r\f]/\n/g ; s/^\s+//; s/\s+$//; } }
 
 # Trim spaces and escape quotes C-style
 sub nicetext {