diff --git a/src/minivhd_create.c b/src/minivhd_create.c
index e1bf916..9e34ece 100644
--- a/src/minivhd_create.c
+++ b/src/minivhd_create.c
@@ -98,7 +98,7 @@ static int mvhd_gen_par_loc(MVHDSparseHeader* header,
     char child_dir[MVHD_MAX_PATH_BYTES] = {0};
     size_t child_dir_len;
     if (strlen(child_path) < sizeof child_dir) {
-        strcpy_s(child_dir, MVHD_MAX_PATH_BYTES, child_path);
+        strcpy(child_dir, child_path);
     } else {
         *err = MVHD_ERR_PATH_LEN;
         rv = -1;
diff --git a/src/minivhd_manage.c b/src/minivhd_manage.c
index 5942e96..75e0953 100644
--- a/src/minivhd_manage.c
+++ b/src/minivhd_manage.c
@@ -171,7 +171,7 @@ static bool mvhd_parent_path_exists(struct MVHDPaths* paths, uint32_t plat_code)
     if (plat_code == MVHD_DIF_LOC_W2RU && *paths->w2ru_path) {
         cwk_ret = cwk_path_join((const char*)paths->dir_path, (const char*)paths->w2ru_path, paths->joined_path, sizeof paths->joined_path);
     } else if (plat_code == MVHD_DIF_LOC_W2KU && *paths->w2ku_path) {
-        strncpy_s(paths->joined_path, sizeof paths->joined_path, (const char*)paths->w2ku_path, sizeof paths->joined_path);
+        memcpy(paths->joined_path, paths->w2ku_path, (sizeof paths->joined_path) - 1);
         cwk_ret = 0;
     } else if (plat_code == 0) {
         cwk_ret = cwk_path_join((const char*)paths->dir_path, (const char*)paths->file_name, paths->joined_path, sizeof paths->joined_path);
@@ -182,7 +182,8 @@ static bool mvhd_parent_path_exists(struct MVHDPaths* paths, uint32_t plat_code)
     f = mvhd_fopen((const char*)paths->joined_path, "rb", &ferr);
     if (f != NULL) {
         /* We found a file at the requested path! */
-        strncpy_s(tmp_open_path, sizeof tmp_open_path, paths->joined_path, sizeof tmp_open_path);
+        memcpy(tmp_open_path, paths->joined_path, (sizeof paths->joined_path) - 1);
+        tmp_open_path[sizeof tmp_open_path - 1] = '\0';
         fclose(f);
         return true;
     } else {
@@ -225,7 +226,7 @@ static char* mvhd_get_diff_parent_path(MVHDMeta* vhdm, int* err) {
         *err = MVHD_ERR_PATH_LEN;
         goto paths_cleanup;
     }
-    strncpy_s(paths->dir_path, sizeof paths->dir_path, vhdm->filename, dirlen);
+    memcpy(paths->dir_path, vhdm->filename, dirlen);
     /* Get the filename field from the sparse header. */
     utf_outlen = (int)sizeof paths->file_name;
     utf_inlen = (int)sizeof vhdm->sparse.par_utf16_name;
@@ -373,7 +374,8 @@ MVHDMeta* mvhd_open(const char* path, bool readonly, int* err) {
         *err = MVHD_ERR_PATH_LEN;
         goto cleanup_vhdm;
     }
-    strcpy_s(vhdm->filename, sizeof vhdm->filename, path);
+    //This is safe, as we've just checked for potential overflow above
+    strcpy(vhdm->filename, path);
     vhdm->f = readonly ? mvhd_fopen((const char*)vhdm->filename, "rb", err) : mvhd_fopen((const char*)vhdm->filename, "rb+", err);
     if (vhdm->f == NULL) {
         /* note, mvhd_fopen sets err for us */
diff --git a/src/minivhd_util.c b/src/minivhd_util.c
index 0994d19..d8f44ca 100644
--- a/src/minivhd_util.c
+++ b/src/minivhd_util.c
@@ -139,8 +139,8 @@ FILE* mvhd_fopen(const char* path, const char* mode, int* err) {
     int path_res = UTF8ToUTF16LE((unsigned char*)new_path, &new_path_len, (const unsigned char*)path, (int*)&path_len);
     int mode_res = UTF8ToUTF16LE((unsigned char*)mode_str, &new_mode_len, (const unsigned char*)mode, (int*)&mode_len);
     if (path_res > 0 && mode_res > 0) {
-        errno_t wfopen_err = _wfopen_s(&f, new_path, mode_str);
-        if (wfopen_err != 0 || f == NULL) {
+        f = _wfopen(new_path, mode_str);
+        if (f == NULL) {
             mvhd_errno = errno;
             *err = MVHD_ERR_FILE;
         }
@@ -320,4 +320,4 @@ uint32_t mvhd_file_mod_timestamp(const char* path, int *err) {
         }
     return mvhd_epoch_to_vhd_ts(file_stat.st_mtime);
 #endif
-}
\ No newline at end of file
+}
diff --git a/src/minivhd_util.h b/src/minivhd_util.h
index 4528b40..df68410 100644
--- a/src/minivhd_util.h
+++ b/src/minivhd_util.h
@@ -3,6 +3,7 @@
 
 #include <stdint.h>
 #include <stdio.h>
+#include <time.h>
 #include "minivhd_internal.h"
 #include "minivhd.h"
 #define MVHD_START_TS 946684800
@@ -132,4 +133,4 @@ uint32_t mvhd_crc32(const void* data, size_t n_bytes);
  * 'err' will be set to non-zero on error
  */
 uint32_t mvhd_file_mod_timestamp(const char* path, int *err);
-#endif
\ No newline at end of file
+#endif