diff --git a/src/libsodium/crypto_pwhash/argon2/argon2-core.c b/src/libsodium/crypto_pwhash/argon2/argon2-core.c
index 8f89e97c..3108fb8f 100644
--- a/src/libsodium/crypto_pwhash/argon2/argon2-core.c
+++ b/src/libsodium/crypto_pwhash/argon2/argon2-core.c
@@ -518,7 +518,7 @@ argon2_initialize(argon2_instance_t *instance, argon2_context *context)
     return ARGON2_OK;
 }
 
-int
+static int
 argon2_pick_best_implementation(void)
 {
 /* LCOV_EXCL_START */
diff --git a/src/libsodium/crypto_pwhash/argon2/argon2-core.h b/src/libsodium/crypto_pwhash/argon2/argon2-core.h
index ccad1355..2fd7f41c 100644
--- a/src/libsodium/crypto_pwhash/argon2/argon2-core.h
+++ b/src/libsodium/crypto_pwhash/argon2/argon2-core.h
@@ -251,7 +251,6 @@ void argon2_finalize(const argon2_context *context,
  */
 typedef void (*fill_segment_fn)(const argon2_instance_t *instance,
                                 argon2_position_t        position);
-int argon2_pick_best_implementation(void);
 void argon2_fill_segment_avx512f(const argon2_instance_t *instance,
                                  argon2_position_t        position);
 void argon2_fill_segment_avx2(const argon2_instance_t *instance,