diff --git a/crc32_simd.h b/crc32_simd.h
index d3d0bce..08f1756 100644
--- a/crc32_simd.h
+++ b/crc32_simd.h
@@ -9,6 +9,7 @@
 
 #include "zconf.h"
 #include "zutil.h"
+#include "deflate.h"
 
 /*
  * crc32_sse42_simd_(): compute the crc32 of the buffer, where the buffer
@@ -33,3 +34,8 @@
                                           const unsigned char* buf,
                                           z_size_t len);
 
+/*
+ * Insert hash string.
+ */
+Pos ZLIB_INTERNAL insert_string_arm(deflate_state *const s, const Pos str);
+