diff --git a/src/core/copyjob.cpp b/src/core/copyjob.cpp
--- a/src/core/copyjob.cpp
+++ b/src/core/copyjob.cpp
@@ -884,7 +884,25 @@
         slotReport();
 
         qCDebug(KIO_COPYJOB_DEBUG)<<"Stating finished. To copy:"<<m_totalSize<<", available:"<<m_freeSpace;
-        //TODO warn user beforehand if space is not enough
+        if (m_totalSize > m_freeSpace) {
+            q->setError(ERR_DISK_FULL);
+            m_bCurrentSrcIsDir ? q->setErrorText(xi18nc("@info", "There is not enough space available at <filename>%1</filename> to hold the folder."
+                                                        "<nl/><nl/>%2 are required but only %3 are available",
+                                                        m_globalDest.toLocalFile(),
+                                                        KIO::convertSize(m_totalSize),
+                                                        KIO::convertSize(m_freeSpace)
+                                                       )
+                                                )
+                               : q->setErrorText(xi18nc("@info", "There is not enough space available at <filename>%1</filename> to hold the file."
+                                                        "<nl/><nl/>%2 are required but only %3 are available",
+                                                        m_globalDest.toLocalFile(),
+                                                        KIO::convertSize(m_totalSize),
+                                                        KIO::convertSize(m_freeSpace)
+                                                       )
+                                                );
+            q->emitResult();
+            return;
+        }
 
         if (!dirs.isEmpty()) {
             emit q->aboutToCreate(q, dirs);