diff --git a/src/signature.c b/src/signature.c
index 00d21abe..2efd5544 100644
--- a/src/signature.c
+++ b/src/signature.c
@@ -177,7 +177,7 @@ void signature_deinit(void)
 	CRYPTO_cleanup_all_ex_data();
 }
 
-bool signature_verify_data(const unsigned char *data, size_t data_len, const unsigned char *sig_data, size_t sig_data_len, enum signature_flags flags)
+bool signature_verify_data(const void *data, size_t data_len, const void *sig_data, size_t sig_data_len, enum signature_flags flags)
 
 {
 	bool result = false;
@@ -267,11 +267,11 @@ bool signature_verify(const char *file, const char *sig_file, enum signature_fla
 
 	int data_fd = -1;
 	size_t data_len;
-	unsigned char *data = NULL;
+	void *data = NULL;
 
 	int sig_fd = -1;
 	size_t sig_len;
-	unsigned char *sig = NULL;
+	void *sig = NULL;
 
 	/* get the signature */
 	sig_fd = open(sig_file, O_RDONLY);
@@ -590,7 +590,7 @@ void signature_print_info(const char UNUSED_PARAM *path)
 	return;
 }
 
-bool signature_verify_data(const unsigned char UNUSED_PARAM *data, size_t UNUSED_PARAM data_len, const unsigned char UNUSED_PARAM *sig_data, size_t UNUSED_PARAM sig_data_len, enum signature_flags UNUSED_PARAM flags)
+bool signature_verify_data(const void UNUSED_PARAM *data, size_t UNUSED_PARAM data_len, const void UNUSED_PARAM *sig_data, size_t UNUSED_PARAM sig_data_len, enum signature_flags UNUSED_PARAM flags)
 {
 	return true;
 }
diff --git a/src/signature.h b/src/signature.h
index a86646e1..25861446 100644
--- a/src/signature.h
+++ b/src/signature.h
@@ -67,7 +67,7 @@ bool signature_verify(const char *file, const char *sig_file, enum signature_fla
  *
  * @return true if the file is signed with certificate used signature_init()
  */
-bool signature_verify_data(const unsigned char *data, size_t data_len, const unsigned char *sig_data, size_t sig_data_len, enum signature_flags flags);
+bool signature_verify_data(const void *data, size_t data_len, const void *sig_data, size_t sig_data_len, enum signature_flags flags);
 
 /**
  * Print extra information about the certificate pointed by PATH.
diff --git a/src/version.c b/src/version.c
index c5b71af6..37a0e912 100644
--- a/src/version.c
+++ b/src/version.c
@@ -138,10 +138,8 @@ static int verify_signature(char *url, struct curl_file_data *tmp_version)
 		goto out;
 	}
 
-	ret = signature_verify_data((const unsigned char *)tmp_version->data,
-				    tmp_version->len,
-				    (const unsigned char *)tmp_version_sig.data,
-				    tmp_version_sig.len,
+	ret = signature_verify_data(tmp_version->data, tmp_version->len,
+				    tmp_version_sig.data, tmp_version_sig.len,
 				    SIGNATURE_PRINT_ERRORS | SIGNATURE_IGNORE_EXPIRATION)
 		  ? 0
 		  : -SWUPD_ERROR_SIGNATURE_VERIFICATION;