diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index d136169c2..6751803f2 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -8,7 +8,7 @@ This file contains a high-level description of this package's evolution. Release
 ## 4.8.0 - TBD
 
 * [Bug Fix][cmake] Correct an issue with parallel filter test logic in CMake-based builds.
-* [Bug Fix] Now allow nc_inq_var_deflate to be called for all formats, not just netCDF-4. This reverts behavior that was changed in the 4.7.4 release. See [https://github.com/Unidata/netcdf-c/issues/1691].
+* [Bug Fix] Now allow nc_inq_var_deflate()/nc_inq_var_szip() to be called for all formats, not just HDF5. Non-HDF5 files return NC_NOERR and report no compression in use. This reverts behavior that was changed in the 4.7.4 release. See [https://github.com/Unidata/netcdf-c/issues/1691].
 
 ## 4.7.4 - March 27, 2020
 
diff --git a/libdispatch/dvarinq.c b/libdispatch/dvarinq.c
index 77ff6208c..7a5e67b04 100644
--- a/libdispatch/dvarinq.c
+++ b/libdispatch/dvarinq.c
@@ -255,8 +255,14 @@ nc_inq_varnatts(int ncid, int varid, int *nattsp)
 		     nattsp);
 }
 
-/** \ingroup variables
-Learn the storage and deflate settings for a variable.
+/** 
+\ingroup variables Learn the storage and deflate settings for a
+variable. 
+
+Deflation is compression with the zlib library. Deflation is only
+available for netCDF/HDF5 files. For classic and other files, this
+function will return shuffle off, deflate off, and a deflate level of
+0.
 
 \param ncid NetCDF or group ID, from a previous call to nc_open(),
 nc_create(), nc_def_grp(), or associated inquiry functions such as
@@ -277,7 +283,6 @@ use, and deflate_levelp is provided, it will get a zero. (This
 behavior is expected by the Fortran APIs). \ref ignored_if_null.
 
 \returns ::NC_NOERR No error.
-\returns ::NC_ENOTNC4 Not a netCDF-4 file.
 \returns ::NC_EBADID Bad ncid.
 \returns ::NC_ENOTVAR Invalid variable ID.
 \author Ed Hartnett, Dennis Heimbigner
@@ -289,7 +294,6 @@ nc_inq_var_deflate(int ncid, int varid, int *shufflep, int *deflatep, int *defla
    size_t nparams;
    unsigned int params[4];
    int deflating = 0;
-   NC_FILE_INFO_T **h5;
    int stat;
    
    stat = NC_check_id(ncid,&ncp);
@@ -651,16 +655,20 @@ Learn the szip settings of a variable.
 
 This function returns the szip settings for a variable. To turn on
 szip compression, use nc_def_var_szip(). Szip compression is only
-available if HDF5 was built with szip support. The nc_def_var_filter
-function may also be used to set szip compression.
+available for netCDF/HDF5 files, and only if HDF5 was built with szip
+support. 
 
-If a variable is not using szip, then a zero will be passed back
-for both options_maskp and pixels_per_blockp.
+If a variable is not using szip, or if this function is called on a
+file that is not a HDF5 file, then a zero will be passed back for both
+options_maskp and pixels_per_blockp.
 
 For more information on HDF5 and szip see
 https://support.hdfgroup.org/HDF5/doc/RM/RM_H5P.html#Property-SetSzip
 and https://support.hdfgroup.org/doc_resource/SZIP/index.html.
 
+The nc_def_var_filter function may also be used to set szip
+compression.
+
 \param ncid NetCDF or group ID, from a previous call to nc_open(),
 nc_create(), nc_def_grp(), or associated inquiry functions such as
 nc_inq_ncid().
@@ -681,12 +689,10 @@ szip is not in use for this variable. \ref ignored_if_null.
 
 \returns ::NC_NOERR No error.
 \returns ::NC_EBADID Bad ncid.
-\returns ::NC_ENOTNC4 Not a netCDF-4 file.
 \returns ::NC_ENOTVAR Invalid variable ID.
 \returns ::NC_EFILTER Filter error.
 
 \author Ed Hartnett, Dennis Heimbigner
-
 */
 int
 nc_inq_var_szip(int ncid, int varid, int *options_maskp, int *pixels_per_blockp)
@@ -707,7 +713,9 @@ nc_inq_var_szip(int ncid, int varid, int *options_maskp, int *pixels_per_blockp)
 	    return NC_EFILTER; /* bad # params */
 	break;
    case NC_ENOFILTER:
-       /* If the szip filter is not in use, return 0 for both  parameters. */
+   case NC_ENOTNC4:
+       /* If the szip filter is not in use, of if this is not a
+	* netCDF/HDF5 file, return 0 for both parameters. */
        params[0] = 0;
        params[1] = 0;
        stat = NC_NOERR;
diff --git a/nc_test/tst_formats.c b/nc_test/tst_formats.c
index cbb0bc708..838923cc6 100644
--- a/nc_test/tst_formats.c
+++ b/nc_test/tst_formats.c
@@ -172,6 +172,7 @@ main(int argc, char **argv)
                int data_in;
                int fill_value = TEST_VAL_42 * 2;
 	       int shuffle_in, deflate_in, deflate_level_in;
+	       int options_mask_in, pixels_per_block_in;
 
                /* Try to set fill mode after data have been written. */
                sprintf(file_name, "%s_%d_%d_%d_elatefill.nc", FILE_NAME_BASE, format[f], d, a);
@@ -186,6 +187,11 @@ main(int argc, char **argv)
 				      &deflate_level_in)) ERR;
 	       if (shuffle_in || deflate_in || deflate_level_in) ERR;
 	       
+	       /* There is no szip on this var, and that is true in
+		* all formats. */
+	       if (nc_inq_var_szip(ncid, varid, &options_mask_in, &pixels_per_block_in)) ERR;
+	       if (options_mask_in || pixels_per_block_in) ERR;
+	       
                if (nc_enddef(ncid)) ERR;
                /* For netCDF-4, we don't actually have to write data to
                 * prevent future setting of the fill value. Once the user