diff --git a/doc/sphinx-guides/source/installation/config.rst b/doc/sphinx-guides/source/installation/config.rst
index 43c33dc0868..421777607c0 100644
--- a/doc/sphinx-guides/source/installation/config.rst
+++ b/doc/sphinx-guides/source/installation/config.rst
@@ -1587,7 +1587,7 @@ dataverse.rserve.port
 Port number for Rserve, used for tasks that require use of R (to ingest RData
 files and to save tabular data as RData frames).
 
-Defaults to ``6311``.
+Defaults to ``6311`` when not configured or no valid integer.
 
 Can also be set via *MicroProfile Config API* sources, e.g. the environment
 variable ``DATAVERSE_RSERVE_PORT``.
diff --git a/src/main/java/edu/harvard/iq/dataverse/ingest/tabulardata/impl/plugins/rdata/RDATAFileReader.java b/src/main/java/edu/harvard/iq/dataverse/ingest/tabulardata/impl/plugins/rdata/RDATAFileReader.java
index 1ec0c389049..6d17a5bd553 100644
--- a/src/main/java/edu/harvard/iq/dataverse/ingest/tabulardata/impl/plugins/rdata/RDATAFileReader.java
+++ b/src/main/java/edu/harvard/iq/dataverse/ingest/tabulardata/impl/plugins/rdata/RDATAFileReader.java
@@ -438,7 +438,14 @@ public RDATAFileReader(TabularDataFileReaderSpi originator) {
     // ready to be overridden by a sysadmin. Every time a file would be read with this file reader,
     // a new reader will be created, reading from the cached config source settings with minimal overhead.
     this.RSERVE_HOST = JvmSettings.RSERVE_HOST.lookup();
-    this.RSERVE_PORT = JvmSettings.RSERVE_PORT.lookup(Integer.class);
+    int port;
+    try {
+      port = JvmSettings.RSERVE_PORT.lookup(Integer.class);
+    } catch (IllegalArgumentException e) {
+      LOG.log(Level.SEVERE, "Could not parse value for " + JvmSettings.RSERVE_PORT.getScopedKey() + ", defaulting to 6311", e);
+      port = 6311;
+    }
+    this.RSERVE_PORT = port;
     this.RSERVE_USER = JvmSettings.RSERVE_USER.lookup();
     this.RSERVE_PASSWORD = JvmSettings.RSERVE_PASSWORD.lookup();