diff --git a/docs/CHANGES.TXT b/docs/CHANGES.TXT
index 54301cd9c..f250da30a 100644
--- a/docs/CHANGES.TXT
+++ b/docs/CHANGES.TXT
@@ -36,6 +36,7 @@
 - Improvement: Use Corrosion to build Rust code
 - Improvement: Ignore MXF Caption Essence Container version byte to enhance SRT subtitle extraction compatibility
 - New: Add tesseract page segmentation modes control with `--psm` flag
+- Fix: Resolve compile-time error about implicit declarations (#1646)
 
 0.94 (2021-12-14)
 -----------------
diff --git a/src/lib_ccx/ocr.c b/src/lib_ccx/ocr.c
index c43ca5589..350e1a19e 100644
--- a/src/lib_ccx/ocr.c
+++ b/src/lib_ccx/ocr.c
@@ -7,6 +7,7 @@
 #include "ccx_common_constants.h"
 #include <dirent.h>
 #include "ccx_encoders_helpers.h"
+#include "ccx_encoders_spupng.h"
 #include "ocr.h"
 #undef OCR_DEBUG