diff --git a/MANIFEST.in b/MANIFEST.in
index 79a939a..13eef7e 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -7,3 +7,4 @@ include fuzzysearch/kmp.h
 include fuzzysearch/memmem.h
 include fuzzysearch/_substitutions_only_lp_template.h
 include fuzzysearch/_substitutions_only_ngrams_template.h
+include fuzzysearch/wordlen_memmem.h
diff --git a/setup.py b/setup.py
index d78ee84..e185dbb 100644
--- a/setup.py
+++ b/setup.py
@@ -32,7 +32,7 @@ _generic_search_module = Extension(
 )
 pymemmem_module = Extension(
     'fuzzysearch._pymemmem',
-    sources=['fuzzysearch/_pymemmem.c', 'fuzzysearch/memmem.c', 'fuzzysearch/kmp.c'],
+    sources=['fuzzysearch/_pymemmem.c', 'fuzzysearch/memmem.c', 'fuzzysearch/kmp.c', 'fuzzysearch/wordlen_memmem.c'],
     include_dirs=['.'],
 )