diff --git a/MANIFEST b/MANIFEST
index d5be43653a6..e2960f6de12 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -1139,6 +1139,7 @@
 ./test/cache_tagging.c
 ./test/chunk_info.c
 ./test/cmpd_dset.c
+./test/cmpd_dtransform.c
 ./test/cork.c
 ./test/corrupt_stab_msg.h5
 ./test/cross_read.c
diff --git a/src/H5T.c b/src/H5T.c
index de2a1002501..587ba0f3aa3 100644
--- a/src/H5T.c
+++ b/src/H5T.c
@@ -3408,8 +3408,8 @@ H5T__create(H5T_class_t type, size_t size)
  * Note:      Common code for both H5T_copy and H5T_copy_reopen, as part of
  *            the const-correct datatype copying routines.
  *
- * Programmer:	David Young
- *	        January 18, 2020
+ * Programmer:  David Young
+ *              January 18, 2020
  *
  *-------------------------------------------------------------------------
  */
@@ -3462,8 +3462,8 @@ H5T__initiate_copy(const H5T_t *old_dt)
  * Return:    Success:    Pointer to a new copy of the OLD_DT argument.
  *            Failure:    NULL
  *
- * Programmer:	David Young
- *	        January 18, 2020
+ * Programmer:  David Young
+ *              January 18, 2020
  *
  *-------------------------------------------------------------------------
  */
@@ -3490,8 +3490,8 @@ H5T__copy_transient(H5T_t *old_dt)
  * Return:    Success:    Pointer to a new copy of the OLD_DT argument.
  *            Failure:    NULL
  *
- * Programmer:	David Young
- *	        January 18, 2020
+ * Programmer:  David Young
+ *              January 18, 2020
  *
  *-------------------------------------------------------------------------
  */
@@ -3521,8 +3521,8 @@ H5T__copy_all(H5T_t *old_dt)
  *
  * Note:      Common code for both H5T_copy and H5T_copy_reopen.
  *
- * Programmer:	David Young
- *	        January 18, 2020
+ * Programmer:  David Young
+ *              January 18, 2020
  *
  *-------------------------------------------------------------------------
  */
@@ -3794,8 +3794,8 @@ H5T_copy(const H5T_t *old_dt, H5T_copy_t method)
  * Return:    Success:    Pointer to a new copy of the OLD_DT argument.
  *            Failure:    NULL
  *
- * Programmer:	David Young
- *	        January 18, 2020
+ * Programmer:  David Young
+ *              January 18, 2020
  *
  *-------------------------------------------------------------------------
  */
@@ -5270,7 +5270,10 @@ H5T__path_find_real(const H5T_t *src, const H5T_t *dst, const char *name, H5T_co
     } /* end else-if */
 
     /* Set the flag to indicate both source and destination types are compound types
-     * for the optimization of data reading (in H5Dio.c). */
+     * for the optimization of data reading (in H5Dio.c).
+     * Make sure that path->are_compounds is only TRUE for compound types.
+     */
+    path->are_compounds = FALSE;
     if (H5T_COMPOUND == H5T_get_class(src, TRUE) && H5T_COMPOUND == H5T_get_class(dst, TRUE))
         path->are_compounds = TRUE;
 
diff --git a/src/H5Ztrans.c b/src/H5Ztrans.c
index 0224c779c37..7d55efd3d1c 100644
--- a/src/H5Ztrans.c
+++ b/src/H5Ztrans.c
@@ -1538,10 +1538,20 @@ H5Z_xform_create(const char *expr)
                     "unable to allocate memory for data transform expression")
 
     /* Find the number of times "x" is used in this equation, and allocate room for storing that many points
+     * A more sophisticated check is needed to support scientific notation.
      */
-    for (i = 0; i < HDstrlen(expr); i++)
-        if (HDisalpha(expr[i]))
+    for (i = 0; i < HDstrlen(expr); i++) {
+        if (HDisalpha(expr[i])) {
+            if ((i > 0) && (i < (HDstrlen(expr) - 1))) {
+                if (((expr[i] == 'E') || (expr[i] == 'e')) &&
+                    (HDisdigit(expr[i - 1]) || (expr[i - 1] == '.')) &&
+                    (HDisdigit(expr[i + 1]) || (expr[i + 1] == '-') || (expr[i + 1] == '+')))
+                    continue;
+            }
+
             count++;
+        }
+    }
 
     /* When there are no "x"'s in the equation (ie, simple transform case),
      * we don't need to allocate any space since no array will have to be
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index ecfce90c12f..28284025590 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -331,6 +331,7 @@ set (H5_TESTS
     thread_id # special link
     vol
     timer
+    cmpd_dtransform
 )
 
 macro (ADD_H5_EXE file)
diff --git a/test/Makefile.am b/test/Makefile.am
index 66bccbbf23b..a60de2d68e6 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -60,7 +60,7 @@ TEST_PROG= testhdf5 \
            cache cache_api cache_image cache_tagging lheap ohdr \
            stab gheap evict_on_close farray earray btree2 fheap \
            pool accum hyperslab istore bittests dt_arith page_buffer \
-           dtypes dsets chunk_info cmpd_dset filter_fail extend direct_chunk \
+           dtypes dsets chunk_info cmpd_dset cmpd_dtransform filter_fail extend direct_chunk \
            external efc objcopy objcopy_ref links unlink twriteorder big mtime \
            fillval mount \
            flush1 flush2 app_ref enum set_extent ttsafe enc_dec_plist \
diff --git a/test/cmpd_dtransform.c b/test/cmpd_dtransform.c
new file mode 100644
index 00000000000..ef5ad750285
--- /dev/null
+++ b/test/cmpd_dtransform.c
@@ -0,0 +1,136 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the COPYING file, which can be found at the root of the source code       *
+ * distribution tree, or in https://www.hdfgroup.org/licenses.               *
+ * If you do not have access to either file, you may request a copy from     *
+ * help@hdfgroup.org.                                                        *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Programmer:  Jan-Willem Blokland
+ *              December 1, 2020
+ *
+ * Purpose:     Test writing compounded attribute followed by
+ *              writing data with a data transform function.
+ */
+
+#include "h5test.h"
+
+#define FILENAME "cmpd_dtransform.h5"
+#define LENGTH   11
+
+typedef struct {
+    char name[64];
+    char unit[64];
+} att_t;
+
+int
+main(void)
+{
+    hsize_t dima[] = {1};
+    hsize_t dims[] = {LENGTH};
+    hid_t   str_dtyp_id, att_dtyp_id, file_id, fspace_id, dset_id, att_dspc_id, att_attr_id, dxpl_id;
+
+    /* Compound datatype */
+    att_t *atts = HDmalloc(sizeof(att_t));
+    HDstrcpy(atts[0].name, "Name");
+    HDstrcpy(atts[0].unit, "Unit");
+
+    /* String type */
+    if ((str_dtyp_id = H5Tcopy(H5T_C_S1)) < 0)
+        TEST_ERROR;
+    H5Tset_size(str_dtyp_id, 64);
+
+    /* Attribute type */
+    if ((att_dtyp_id = H5Tcreate(H5T_COMPOUND, sizeof(att_t))) < 0)
+        TEST_ERROR;
+    H5Tinsert(att_dtyp_id, "NAME", HOFFSET(att_t, name), str_dtyp_id);
+    H5Tinsert(att_dtyp_id, "UNIT", HOFFSET(att_t, unit), str_dtyp_id);
+
+    /* Create file. */
+    if ((file_id = H5Fcreate(FILENAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+
+    /* Create file dataspace. */
+    if ((fspace_id = H5Screate_simple(1, dims, NULL)) < 0)
+        TEST_ERROR;
+
+    /* Create dataset. */
+    if ((dset_id = H5Dcreate2(file_id, "test_dset", H5T_NATIVE_INT, fspace_id, H5P_DEFAULT, H5P_DEFAULT,
+                              H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+
+    /* Write the attribute (compound) to the dataset */
+    if ((att_dspc_id = H5Screate_simple(1, dima, NULL)) < 0)
+        TEST_ERROR;
+    if ((att_attr_id =
+             H5Acreate2(dset_id, "ATTRIBUTES", att_dtyp_id, att_dspc_id, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+    if (H5Awrite(att_attr_id, att_dtyp_id, atts) < 0)
+        TEST_ERROR;
+
+    /* Create dataset transfer property list */
+    const char *expr = "2*x";
+    if ((dxpl_id = H5Pcreate(H5P_DATASET_XFER)) < 0)
+        TEST_ERROR;
+    if (H5Pset_data_transform(dxpl_id, expr) < 0) {
+        HDprintf("**** ERROR: H5Pset_data_transform (expression: %s) ****\n", expr);
+        TEST_ERROR;
+    }
+
+    int *data     = HDmalloc(LENGTH * sizeof(int));
+    int *data_res = HDmalloc(LENGTH * sizeof(int));
+    for (unsigned i = 0; i < LENGTH; i++) {
+        data[i]     = 10;
+        data_res[i] = 2 * data[i];
+    }
+
+    /* Write the data */
+    if (H5Dwrite(dset_id, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, dxpl_id, data) < 0)
+        TEST_ERROR;
+
+    /* Read attribute */
+    att_t *atts_res = HDmalloc(sizeof(att_t));
+    if (H5Aread(att_attr_id, att_dtyp_id, atts_res) < 0)
+        TEST_ERROR;
+
+    /* Verify attribute */
+    if (HDstrcmp(atts_res[0].name, atts[0].name) != 0)
+        TEST_ERROR;
+    if (HDstrcmp(atts_res[0].unit, atts[0].unit) != 0)
+        TEST_ERROR;
+
+    /* Read the data */
+    if (H5Dread(dset_id, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, data) < 0)
+        TEST_ERROR;
+
+    /* Verify data */
+    for (unsigned idx = 0; idx < LENGTH; idx++) {
+        if (data[idx] != data_res[idx])
+            TEST_ERROR;
+    }
+
+    HDfree(atts);
+    HDfree(atts_res);
+    HDfree(data);
+    HDfree(data_res);
+
+    /* Close all identifiers. */
+    H5Pclose(dxpl_id);
+    H5Aclose(att_attr_id);
+    H5Sclose(att_dspc_id);
+    H5Dclose(dset_id);
+    H5Sclose(fspace_id);
+    H5Fclose(file_id);
+    H5Tclose(att_dtyp_id);
+    H5Tclose(str_dtyp_id);
+
+    return 0;
+
+error:
+    return 1;
+}
diff --git a/test/dtransform.c b/test/dtransform.c
index c679d30a74b..9445d83eb17 100644
--- a/test/dtransform.c
+++ b/test/dtransform.c
@@ -581,6 +581,7 @@ test_specials(hid_t file)
     const char *special3 = "1000/x";
     const char *special4 = "-x";
     const char *special5 = "+x";
+    const char *special6 = "2e+1*x";
 
     TESTING("data transform of some special cases")
 
@@ -702,6 +703,29 @@ test_specials(hid_t file)
 
     COMPARE_INT(read_buf, data_res)
 
+    if (H5Dclose(dset_id) < 0)
+        TEST_ERROR
+
+    /*-----------------------------
+     * Operation 6: 2e+1*x
+     *----------------------------*/
+    if (H5Pset_data_transform(dxpl_id, special6) < 0)
+        TEST_ERROR;
+
+    for (row = 0; row < ROWS; row++)
+        for (col = 0; col < COLS; col++)
+            data_res[row][col] = transformData[row][col] * 20;
+
+    if ((dset_id = H5Dcreate2(file, "/special6", H5T_NATIVE_INT, dataspace, H5P_DEFAULT, H5P_DEFAULT,
+                              H5P_DEFAULT)) < 0)
+        TEST_ERROR
+    if (H5Dwrite(dset_id, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, dxpl_id, transformData) < 0)
+        TEST_ERROR
+    if (H5Dread(dset_id, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, read_buf) < 0)
+        TEST_ERROR
+
+    COMPARE_INT(read_buf, data_res)
+
     if (H5Dclose(dset_id) < 0)
         TEST_ERROR