diff --git a/secp256k1-sys/depend/secp256k1/src/util.h b/secp256k1-sys/depend/secp256k1/src/util.h
index b4ba0b38d..3975b3eca 100644
--- a/secp256k1-sys/depend/secp256k1/src/util.h
+++ b/secp256k1-sys/depend/secp256k1/src/util.h
@@ -11,7 +11,6 @@
 
 #include <stdlib.h>
 #include <stdint.h>
-#include <stdio.h>
 #include <limits.h>
 
 #define STR_(x) #x
@@ -19,26 +18,6 @@
 #define DEBUG_CONFIG_MSG(x) "DEBUG_CONFIG: " x
 #define DEBUG_CONFIG_DEF(x) DEBUG_CONFIG_MSG(#x "=" STR(x))
 
-/* Debug helper for printing arrays of unsigned char. */
-#define PRINT_BUF(buf, len) do { \
-    printf("%s[%lu] = ", #buf, (unsigned long)len); \
-    print_buf_plain(buf, len); \
-} while(0)
-
-static void print_buf_plain(const unsigned char *buf, size_t len) {
-    size_t i;
-    printf("{");
-    for (i = 0; i < len; i++) {
-        if (i % 8 == 0) {
-            printf("\n    ");
-        } else {
-            printf(" ");
-        }
-        printf("0x%02X,", buf[i]);
-    }
-    printf("\n}\n");
-}
-
 # if (!defined(__STDC_VERSION__) || (__STDC_VERSION__ < 199901L) )
 #  if SECP256K1_GNUC_PREREQ(2,7)
 #   define SECP256K1_INLINE __inline__
diff --git a/secp256k1-sys/depend/util.h.patch b/secp256k1-sys/depend/util.h.patch
index 764482596..3135cec7c 100644
--- a/secp256k1-sys/depend/util.h.patch
+++ b/secp256k1-sys/depend/util.h.patch
@@ -1,4 +1,27 @@
-148,152c148,150
+14d13
+< #include <stdio.h>
+22,41d20
+< /* Debug helper for printing arrays of unsigned char. */
+< #define PRINT_BUF(buf, len) do { \
+<     printf("%s[%lu] = ", #buf, (unsigned long)len); \
+<     print_buf_plain(buf, len); \
+< } while(0)
+< 
+< static void print_buf_plain(const unsigned char *buf, size_t len) {
+<     size_t i;
+<     printf("{");
+<     for (i = 0; i < len; i++) {
+<         if (i % 8 == 0) {
+<             printf("\n    ");
+<         } else {
+<             printf(" ");
+<         }
+<         printf("0x%02X,", buf[i]);
+<     }
+<     printf("\n}\n");
+< }
+< 
+148,152c127,129
 <     void *ret = malloc(size);
 <     if (ret == NULL) {
 <         secp256k1_callback_call(cb, "Out of memory");