diff --git a/librz/include/rz_util/rz_file.h b/librz/include/rz_util/rz_file.h
index 14ffeb5038..24e0962d29 100644
--- a/librz/include/rz_util/rz_file.h
+++ b/librz/include/rz_util/rz_file.h
@@ -54,7 +54,7 @@ RZ_API ut8 *rz_deflate(RZ_NONNULL const ut8 *src, int srcLen, int *srcConsumed,
 RZ_API ut8 *rz_file_gzslurp(const char *str, int *outlen, int origonfail);
 RZ_API char *rz_stdin_slurp(int *sz);
 RZ_API RZ_OWN char *rz_file_slurp(const char *str, RZ_NULLABLE size_t *usz);
-RZ_API char *rz_file_slurp_range(const char *str, ut64 off, int sz, int *osz);
+RZ_API RZ_OWN char *rz_file_slurp_range(RZ_NONNULL const char *str, ut64 off, int sz, RZ_OUT RZ_NULLABLE int *osz);
 RZ_API char *rz_file_slurp_random_line(const char *file);
 RZ_API char *rz_file_slurp_random_line_count(const char *file, int *linecount);
 RZ_API ut8 *rz_file_slurp_hexpairs(const char *str, int *usz);
diff --git a/librz/util/file.c b/librz/util/file.c
index b117c33f89..7db372e1e1 100644
--- a/librz/util/file.c
+++ b/librz/util/file.c
@@ -592,7 +592,19 @@ RZ_API ut8 *rz_file_slurp_hexpairs(const char *str, int *usz) {
 	return ret;
 }
 
-RZ_API char *rz_file_slurp_range(const char *str, ut64 off, int sz, int *osz) {
+/**
+ * \brief Reads \p sz bytes from the file \p str at \p off. Note, this function
+ * doesn't support files larger than INT_MAX bytes  currently.
+ *
+ * \param str The file name.
+ * \param off The offset to start reading in the file.
+ * \param sz The number of bytes to read.
+ * \param osz If not NULL, the number of bytes read.
+ *
+ * \return Buffer with the read content. The buffer is always '\0' terminated.
+ */
+RZ_API RZ_OWN char *rz_file_slurp_range(RZ_NONNULL const char *str, ut64 off, int sz, RZ_OUT RZ_NULLABLE int *osz) {
+	rz_return_val_if_fail(str, NULL);
 	char *ret;
 	size_t read_items;
 	FILE *fd = rz_sys_fopen(str, "rb");