diff --git a/scripts/process_gperf.py b/scripts/process_gperf.py
index 7578888..2e55060 100755
--- a/scripts/process_gperf.py
+++ b/scripts/process_gperf.py
@@ -101,7 +101,7 @@
 
     # Replace length lookups with constant len of 4 since we're always
     # looking at pointers
-    line = re.sub(r'lengthtable[[]key[]]', r'4', line)
+    line = re.sub(r'lengthtable\[key\]', r'4', line)
 
     # Empty wordlist entries to have NULLs instead of ""
     line = re.sub(r'[{]["]["][}]', r'{}', line)