diff --git a/testpar/t_vfd.c b/testpar/t_vfd.c
index 93fa4992b55..3b924784ee3 100644
--- a/testpar/t_vfd.c
+++ b/testpar/t_vfd.c
@@ -4216,22 +4216,21 @@ static unsigned
 vector_write_test_8(int file_name_id, int mpi_rank, int mpi_size, H5FD_mpio_xfer_t xfer_mode,
                     H5FD_mpio_collective_opt_t coll_opt_mode, const char *vfd_name)
 {
-    const char *fcn_name = "vector_write_test_8()";
-    char        test_title[120];
-    char        filename[512];
-    haddr_t     eoa;
-    haddr_t     base_addr;
-    bool        show_progress = false;
-    hid_t       fapl_id       = H5I_INVALID_HID; /* file access property list ID */
-    hid_t       dxpl_id       = H5I_INVALID_HID; /* data access property list ID */
-    H5FD_t     *lf            = NULL;            /* VFD struct ptr               */
-    int         cp            = 0;
-    int         i;
-    int         base_index;
-    uint32_t    count = 0;
-    size_t      sizes[4];
-    H5FD_mem_t  types[2];
-
+    const char  *fcn_name = "vector_write_test_8()";
+    char         test_title[120];
+    char         filename[512];
+    haddr_t      eoa;
+    haddr_t      base_addr;
+    bool         show_progress = false;
+    hid_t        fapl_id       = H5I_INVALID_HID; /* file access property list ID */
+    hid_t        dxpl_id       = H5I_INVALID_HID; /* data access property list ID */
+    H5FD_t      *lf            = NULL;            /* VFD struct ptr               */
+    int          cp            = 0;
+    int          i;
+    int          base_index;
+    uint32_t     count = 0;
+    size_t       sizes[4];
+    H5FD_mem_t   types[2];
     haddr_t     *tt_addrs = NULL; /* For storing addrs */
     const void **tt_bufs  = NULL; /* For storing buf pointers */
 
@@ -4629,6 +4628,9 @@ test_vector_io(int mpi_rank, int mpi_size)
                                  H5FD_SUBFILING_NAME);
 #endif
 
+    /* discard the file image buffers */
+    free_file_images();
+
     nerrors += (int)nerrs;
 
     /* return(nerrs);*/
@@ -5955,15 +5957,14 @@ test_selection_io_types_1d(int mpi_rank, int mpi_size, H5FD_t *lf, hid_t dxpl, H
 static void
 test_selection_io_real(int mpi_rank, int mpi_size, H5FD_t *lf, hid_t dxpl)
 {
-    hid_t   mem_spaces[2]  = {H5I_INVALID_HID, H5I_INVALID_HID}; /* memory dataspaces vector */
-    hid_t   file_spaces[2] = {H5I_INVALID_HID, H5I_INVALID_HID}; /* file dataspaces vector */
-    hsize_t dims1[1];                                            /* 1d dimension sizes */
-    hsize_t dims2[2];                                            /* 2d dimension sizes */
-
-    H5FD_mem_t type;                                          /* File type */
-    haddr_t    addrs[2];                                      /* File allocation address */
-    size_t     element_sizes[2] = {sizeof(int), sizeof(int)}; /* Element size */
-    size_t     bufsize;                                       /* Buffer size */
+    hid_t      mem_spaces[2]  = {H5I_INVALID_HID, H5I_INVALID_HID}; /* memory dataspaces vector */
+    hid_t      file_spaces[2] = {H5I_INVALID_HID, H5I_INVALID_HID}; /* file dataspaces vector */
+    hsize_t    dims1[1];                                            /* 1d dimension sizes */
+    hsize_t    dims2[2];                                            /* 2d dimension sizes */
+    H5FD_mem_t type;                                                /* File type */
+    haddr_t    addrs[2];                                            /* File allocation address */
+    size_t     element_sizes[2] = {sizeof(int), sizeof(int)};       /* Element size */
+    size_t     bufsize;                                             /* Buffer size */
     int        i;
     int        j;
 
@@ -6059,18 +6060,30 @@ test_selection_io_real(int mpi_rank, int mpi_size, H5FD_t *lf, hid_t dxpl)
     }
 
     /* Free the buffers */
-    if (wbuf1)
+    if (wbuf1) {
         free(wbuf1);
-    if (wbuf2)
+        wbuf1 = NULL;
+    }
+    if (wbuf2) {
         free(wbuf2);
-    if (fbuf1)
+        wbuf2 = NULL;
+    }
+    if (fbuf1) {
         free(fbuf1);
-    if (fbuf2)
+        fbuf1 = NULL;
+    }
+    if (fbuf2) {
         free(fbuf2);
-    if (erbuf1)
+        fbuf2 = NULL;
+    }
+    if (erbuf1) {
         free(erbuf1);
-    if (erbuf2)
+        erbuf1 = NULL;
+    }
+    if (erbuf2) {
         free(erbuf2);
+        erbuf2 = NULL;
+    }
 
     CHECK_PASSED();
 
@@ -6085,11 +6098,10 @@ test_selection_io_real(int mpi_rank, int mpi_size, H5FD_t *lf, hid_t dxpl)
 static void
 test_selection_io(int mpi_rank, int mpi_size)
 {
-    H5FD_t  *lf   = NULL;            /* VFD struct ptr */
-    hid_t    fapl = H5I_INVALID_HID; /* File access property list */
-    char     filename[1024];         /* Test file name */
-    unsigned flags = 0;              /* File access flags */
-
+    H5FD_t  *lf   = NULL;                     /* VFD struct ptr */
+    hid_t    fapl = H5I_INVALID_HID;          /* File access property list */
+    char     filename[1024];                  /* Test file name */
+    unsigned flags = 0;                       /* File access flags */
     unsigned collective;                      /* Types of I/O for testing */
     hid_t    dxpl          = H5I_INVALID_HID; /* Dataset transfer property list */
     hid_t    def_dxpl      = H5I_INVALID_HID; /* dxpl: independent access */
@@ -6309,9 +6321,6 @@ main(int argc, char **argv)
         printf("===================================\n");
     }
 
-    /* discard the file image buffers */
-    free_file_images();
-
     /* close HDF5 library */
     H5close();