diff --git a/DESCRIPTION b/DESCRIPTION
index 18a614b1..f7c8ec14 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: Spectra
 Title: Spectra Infrastructure for Mass Spectrometry Data
-Version: 1.13.2
+Version: 1.13.3
 Description: The Spectra package defines an efficient infrastructure
    for storing and handling mass spectrometry spectra and functionality to
    subset, process, visualize and compare spectra data. It provides different
diff --git a/NEWS.md b/NEWS.md
index bd40e31c..1800f8ff 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,10 @@
 # Spectra 1.13
 
+## Changes in 1.13.3
+
+- Fix issue in `setBackend` that might cause chunk-wise processing to be not
+  run.
+
 ## Changes in 1.13.2
 
 - Add possibility to enable and perform chunk-wise (parallel) processing to
diff --git a/R/Spectra.R b/R/Spectra.R
index b1efc2a2..b3230ddb 100644
--- a/R/Spectra.R
+++ b/R/Spectra.R
@@ -1551,7 +1551,7 @@ setMethod(
     "setBackend", c("Spectra", "MsBackend"),
     function(object, backend, f = processingChunkFactor(object), ...,
              BPPARAM = bpparam()) {
-        backend_class <- class(object@backend)
+        backend_class <- class(object@backend)[1L]
         BPPARAM <- backendBpparam(object@backend, BPPARAM)
         BPPARAM <- backendBpparam(backend, BPPARAM)
         if (!supportsSetBackend(backend))
@@ -1562,7 +1562,7 @@ setMethod(
         } else {
             if (!is.factor(f))
                 f <- force(factor(f, levels = unique(f)))
-            if (length(f) && length(levels(f) > 1)) {
+            if (length(f) && (length(levels(f)) > 1)) {
                 if (length(f) != length(object))
                     stop("length of 'f' has to match the length of 'object'")
                 bknds <- bplapply(