diff --git a/NEWS.md b/NEWS.md
index 56617d32b..e915f6f21 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -14,6 +14,8 @@
 
 ## Bug fixes
 
+* mkvmerge: fixed that the error message "not enough space on disk" was shown
+  twice on some operating systems. Fixes #1850.
 * mkvmerge, Matroska: if a codec delay is set for a track in the input file,
   it is kept. Fixes #1849.
 * GUI: multiplexer: changing default values in the prerefences (e.g. the
diff --git a/src/merge/output_control.cpp b/src/merge/output_control.cpp
index 8d20536ea..4600d3db1 100644
--- a/src/merge/output_control.cpp
+++ b/src/merge/output_control.cpp
@@ -264,6 +264,10 @@ sighandler(int /* signum */) {
 
   mxinfo(Y(" done\n"));
 
+  // Manually close s_out because cleanup() will discard any remaining
+  // write buffer content in s_out.
+  s_out->close();
+
   cleanup();
 
   mxerror(Y("mkvmerge was interrupted by a SIGINT (Ctrl+C?)\n"));
@@ -2090,7 +2094,18 @@ destroy_readers() {
 */
 void
 cleanup() {
-  s_out.reset();
+  if (s_out) {
+    // If cleanup was called as a result of an exception during
+    // writing due to the file system being full, the destructor would
+    // normally write remaining buffered before closing the file. This
+    // would lead to another exception and another error
+    // message. However, the regular paths all close the file
+    // manually. Therefore any buffered content remaining at this
+    // point can only be due to an error having occurred. The content
+    // can therefore be discarded.
+    dynamic_cast<mm_write_buffer_io_c &>(*s_out).discard_buffer();
+    s_out.reset();
+  }
 
   g_cluster_helper.reset();