diff --git a/doc/xml/release.xml b/doc/xml/release.xml
index 3d4aa84ad..4e9afd9cb 100644
--- a/doc/xml/release.xml
+++ b/doc/xml/release.xml
@@ -57,6 +57,10 @@
                     <release-item>
                         <p>Simplify try..catch..finally names.</p>
                     </release-item>
+
+                    <release-item>
+                        <p>Inflate performance improvement for gzip filter.</p>
+                    </release-item>
                 </release-refactor-list>
             </release-core-list>
 
@@ -78,6 +82,10 @@
                     <release-item>
                         <p>Update Debian/Ubuntu containers to download latest version of <file>pip</file>.</p>
                     </release-item>
+
+                    <release-item>
+                        <p>Full unit test coverage for gzip filter.</p>
+                    </release-item>
                 </release-refactor-list>
             </release-test-list>
         </release>
diff --git a/lib/pgBackRest/Storage/Filter/Gzip.pm b/lib/pgBackRest/Storage/Filter/Gzip.pm
index 144b9efae..e5a1cd3b7 100644
--- a/lib/pgBackRest/Storage/Filter/Gzip.pm
+++ b/lib/pgBackRest/Storage/Filter/Gzip.pm
@@ -156,29 +156,26 @@ sub read
     else
     {
         # If the local buffer size is not large enough to satisfy the request and there is still data to decompress
-        if ($self->{lUncompressedBufferSize} < $iSize)
+        while ($self->{lUncompressedBufferSize} < $iSize && !$self->parent()->eof())
         {
-            while ($self->{lUncompressedBufferSize} < $iSize)
+            if (!defined($self->{tCompressedBuffer}) || length($self->{tCompressedBuffer}) == 0)
             {
-                if (!defined($self->{tCompressedBuffer}) || length($self->{tCompressedBuffer}) == 0)
-                {
-                    $self->parent()->read(\$self->{tCompressedBuffer}, $self->{lCompressBufferMax});
-                }
-
-                my $iZLibStatus = $self->{oZLib}->inflate($self->{tCompressedBuffer}, $self->{tUncompressedBuffer});
-                $self->{lUncompressedBufferSize} = length($self->{tUncompressedBuffer});
-
-                last if $iZLibStatus == Z_STREAM_END;
-
-                $self->errorCheck($iZLibStatus);
+                $self->parent()->read(\$self->{tCompressedBuffer}, $self->{lCompressBufferMax});
             }
+
+            my $iZLibStatus = $self->{oZLib}->inflate($self->{tCompressedBuffer}, $self->{tUncompressedBuffer});
+            $self->{lUncompressedBufferSize} = length($self->{tUncompressedBuffer});
+
+            last if $iZLibStatus == Z_STREAM_END;
+
+            $self->errorCheck($iZLibStatus);
         }
 
         # Actual size is the lesser of the local buffer size or requested size - if the local buffer is smaller than the requested
         # size it means that there was nothing more to be read
         my $iActualSize = $self->{lUncompressedBufferSize} < $iSize ? $self->{lUncompressedBufferSize} : $iSize;
 
-        # Append the to the request buffer
+        # Append to the request buffer
         $$rtBuffer .= substr($self->{tUncompressedBuffer}, 0, $iActualSize);
 
         # Truncate local buffer
@@ -206,7 +203,7 @@ sub write
         $self->errorCheck($self->{oZLib}->deflate($$rtBuffer, $self->{tCompressedBuffer}));
 
         # Only write when buffer is full
-        if (defined($self->{tCompressedBuffer}) && length($self->{tCompressedBuffer}) > $self->{lCompressBufferMax})
+        if (length($self->{tCompressedBuffer}) > $self->{lCompressBufferMax})
         {
             $self->parent()->write(\$self->{tCompressedBuffer});
             $self->{tCompressedBuffer} = undef;
@@ -260,6 +257,8 @@ sub close
         # Close io
         return $self->parent()->close();
     }
+
+    return false;
 }
 
 1;
diff --git a/test/lib/pgBackRestTest/Common/DefineTest.pm b/test/lib/pgBackRestTest/Common/DefineTest.pm
index 3f3ea2ef5..266ea3d26 100644
--- a/test/lib/pgBackRestTest/Common/DefineTest.pm
+++ b/test/lib/pgBackRestTest/Common/DefineTest.pm
@@ -329,7 +329,7 @@ my $oTestDef =
 
                     &TESTDEF_COVERAGE =>
                     {
-                        'Storage/Filter/Gzip' => TESTDEF_COVERAGE_PARTIAL,
+                        'Storage/Filter/Gzip' => TESTDEF_COVERAGE_FULL,
                     },
                 },
                 {
diff --git a/test/lib/pgBackRestTest/Module/Storage/StorageFilterGzipTest.pm b/test/lib/pgBackRestTest/Module/Storage/StorageFilterGzipTest.pm
index 11d8977e9..9e4aa895d 100644
--- a/test/lib/pgBackRestTest/Module/Storage/StorageFilterGzipTest.pm
+++ b/test/lib/pgBackRestTest/Module/Storage/StorageFilterGzipTest.pm
@@ -63,7 +63,8 @@ sub run
     {
         #---------------------------------------------------------------------------------------------------------------------------
         my $oGzipIo = $self->testResult(
-            sub {new pgBackRest::Storage::Filter::Gzip($oDriver->openWrite($strFileGz))}, '[object]', 'new write compress');
+            sub {new pgBackRest::Storage::Filter::Gzip($oDriver->openWrite($strFileGz), {lCompressBufferMax => 4})},
+            '[object]', 'new write compress');
 
         my $tBuffer = substr($strFileContent, 0, 2);
         $self->testResult(sub {$oGzipIo->write(\$tBuffer)}, 2, '    write 2 bytes');
@@ -125,6 +126,7 @@ sub run
         $self->testResult(sub {$oGzipIo->read(\$tBuffer, 2)}, 0, '    read 0 bytes');
 
         $self->testResult(sub {$oGzipIo->close()}, true, '    close');
+        $self->testResult(sub {$oGzipIo->close()}, false, '    close again');
         $self->testResult($tBuffer, $strFileContent, '    check content');
 
         storageTest()->remove($strFileGz);