diff --git a/src/modules/fsresizer/ResizeFSJob.cpp b/src/modules/fsresizer/ResizeFSJob.cpp
index 0589e1866..254e80adb 100644
--- a/src/modules/fsresizer/ResizeFSJob.cpp
+++ b/src/modules/fsresizer/ResizeFSJob.cpp
@@ -33,6 +33,7 @@
 #include "JobQueue.h"
 #include "GlobalStorage.h"
 
+#include "utils/CalamaresUtils.h"
 #include "utils/Logger.h"
 #include "utils/Units.h"
 
@@ -68,7 +69,7 @@ ResizeFSJob::RelativeSize::RelativeSize( const QString& s)
 {
     matchUnitSuffix( s, "%", Percent, m_value, m_unit );
     matchUnitSuffix( s, "MiB", Absolute, m_value, m_unit );
-    
+
     if ( ( unit() == Percent ) && ( value() > 100 ) )
     {
         cDebug() << "Percent value" << value() << "is not valid.";
@@ -87,7 +88,7 @@ ResizeFSJob::RelativeSize::apply( qint64 totalSectors , qint64 sectorSize )
         return -1;
     if ( sectorSize < 1 )
         return -1;
-    
+
     switch( m_unit )
     {
     case None:
@@ -113,6 +114,7 @@ ResizeFSJob::RelativeSize::apply( Device* d )
 
 ResizeFSJob::ResizeFSJob( QObject* parent )
     : Calamares::CppJob( parent )
+    , m_required( false )
 {
 }
 
@@ -156,7 +158,7 @@ ResizeFSJob::findPartition( CoreBackend* backend )
 }
 
 /** @brief Returns the last sector the matched partition should occupy.
- * 
+ *
  * Returns a sector number. Returns -1 if something is wrong (e.g.
  * can't resize at all, or missing data). Returns 0 if the resize
  * won't fit because it doesn't satisfy the settings for atleast
@@ -223,7 +225,7 @@ ResizeFSJob::findGrownEnd(ResizeFSJob::PartitionMatch m)
         cDebug() << ".. only growing by" << wanted << "instead of full" << expand;
         last_available -= ( expand - wanted );
     }
-    
+
     return last_available;
 }
 
@@ -300,7 +302,7 @@ ResizeFSJob::exec()
             << "skipped as not-useful.";
         return Calamares::JobResult::ok();
     }
-        
+
     if ( ( new_end > 0 ) && ( new_end > m.second->lastSector() ) )
     {
         ResizeOperation op( *m.first, *m.second, m.second->firstSector(), new_end );
@@ -334,6 +336,8 @@ ResizeFSJob::setConfigurationMap( const QVariantMap& configurationMap )
 
     m_size = RelativeSize( configurationMap["size"].toString() );
     m_atleast = RelativeSize( configurationMap["atleast"].toString() );
+
+    m_required = CalamaresUtils::getBool( configurationMap, "required", false );
 }
 
 CALAMARES_PLUGIN_FACTORY_DEFINITION( ResizeFSJobFactory, registerPlugin<ResizeFSJob>(); )
diff --git a/src/modules/fsresizer/ResizeFSJob.h b/src/modules/fsresizer/ResizeFSJob.h
index 063495e7d..c34ccb865 100644
--- a/src/modules/fsresizer/ResizeFSJob.h
+++ b/src/modules/fsresizer/ResizeFSJob.h
@@ -68,19 +68,19 @@ public:
          *
          * Each sector has size @p sectorSize , for converting absolute
          * sizes in MiB to sector counts.
-         * 
+         *
          * For invalid sizes, returns -1.
          * For absolute sizes, returns the number of sectors needed.
          * For percent sizes, returns that percent of the number of sectors.
          */
         qint64 apply( qint64 totalSectors, qint64 sectorSize );
-        
+
         /** @brief Apply this size to the given device.
-         * 
+         *
          * Equivalent to apply( d->totalLogical(), d->logicalSize() )
          */
         qint64 apply( Device* d );
-        
+
     private:
         int m_value;
         Unit m_unit;
@@ -107,6 +107,7 @@ private:
     RelativeSize m_atleast;
     QString m_fsname;  // Either this, or devicename, is set, not both
     QString m_devicename;
+    bool m_required;
 
     using PartitionMatch = QPair<Device*, Partition*>;
     /** @brief Find the configured FS using KPMCore @p backend */
diff --git a/src/modules/fsresizer/fsresizer.conf b/src/modules/fsresizer/fsresizer.conf
index 06141fc7d..33329248d 100644
--- a/src/modules/fsresizer/fsresizer.conf
+++ b/src/modules/fsresizer/fsresizer.conf
@@ -12,7 +12,7 @@
 # Which FS needs to be grown? Choose one way to identify it:
 #  - *fs* names a mount point which should already be mounted
 #    in the system.
-#  - *dev* names a device 
+#  - *dev* names a device
 fs: /
 # dev: /dev/mmcblk0p1
 
@@ -33,5 +33,17 @@ size: 100%
 # size, as above. If missing, then it's assumed to be 0,
 # which means resizing is always worthwhile.
 #
+# If *atleast* is not zero, then the setting *required*,
+# below, becomes relevant.
+#
 # Percentages apply to **total device size**.
-atleast: 1000MiB
+#atleast: 1000MiB
+
+# When *atleast* is not zero, then the resize may be
+# recommended (the default) or **required**. If the
+# resize is required and cannot be carried out (because
+# there's not enough space), then that is a fatal
+# error for the installer. By default, resize is only
+# recommended and it is not an error for no resize to be
+# carried out.
+required: false