diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8da238a6..220adeb6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -71,10 +71,12 @@ set(JWT_SOURCES libjwt/base64.c
 add_library(builder OBJECT)
 target_sources(builder PRIVATE libjwt/jwt-common.c)
 target_compile_definitions(builder PRIVATE JWT_BUILDER)
+set_property(TARGET builder PROPERTY POSITION_INDEPENDENT_CODE ON)
 
 add_library(checker OBJECT)
 target_sources(checker PRIVATE libjwt/jwt-common.c)
 target_compile_definitions(checker PRIVATE JWT_CHECKER)
+set_property(TARGET checker PROPERTY POSITION_INDEPENDENT_CODE ON)
 
 target_link_libraries(jwt PRIVATE builder checker)
 target_link_libraries(jwt_static PRIVATE builder checker)
diff --git a/libjwt/jwt-common.c b/libjwt/jwt-common.c
index afecba6f..b595fcc2 100644
--- a/libjwt/jwt-common.c
+++ b/libjwt/jwt-common.c
@@ -63,7 +63,7 @@ jwt_common_t *FUNC(new)(void)
 	return __cmd;
 }
 
-int FUNC(setkey_check)(jwt_common_t *__cmd, const jwt_alg_t alg,
+static int __setkey_check(jwt_common_t *__cmd, const jwt_alg_t alg,
 		       const jwk_item_t *key)
 {
 	if (__cmd == NULL)
@@ -103,7 +103,7 @@ int FUNC(setkey_check)(jwt_common_t *__cmd, const jwt_alg_t alg,
 int FUNC(setkey)(jwt_common_t *__cmd, const jwt_alg_t alg,
 		 const jwk_item_t *key)
 {
-	if (FUNC(setkey_check)(__cmd, alg, key))
+	if (__setkey_check(__cmd, alg, key))
 		return 1;
 
 	__cmd->c.alg = alg;
@@ -465,7 +465,7 @@ char *FUNC(generate)(jwt_common_t *__cmd)
 	}
 
 	/* Callback may have changed this */
-	if (FUNC(setkey_check)(__cmd, config.alg, config.key)) {
+	if (__setkey_check(__cmd, config.alg, config.key)) {
 		jwt_write_error(__cmd, "Algorithm and key returned by callback invalid");
 		return NULL;
 	}
diff --git a/libjwt/jwt-private.h b/libjwt/jwt-private.h
index 15baebce..d6bbbfbb 100644
--- a/libjwt/jwt-private.h
+++ b/libjwt/jwt-private.h
@@ -248,13 +248,6 @@ JWT_NO_EXPORT
 jwt_t *jwt_verify_complete(jwt_t *jwt, const jwt_config_t *config,
 			   const char *token, unsigned int payload_len);
 
-JWT_NO_EXPORT
-int jwt_builder_setkey_check(jwt_builder_t *builder, const jwt_alg_t alg,
-			     const jwk_item_t *key);
-JWT_NO_EXPORT
-int jwt_checker_setkey_check(jwt_checker_t *checker, const jwt_alg_t alg,
-			     const jwk_item_t *key);
-
 JWT_NO_EXPORT
 char *jwt_encode_str(jwt_t *jwt);