diff --git a/assembly/src/main/filtered-resources/unix/bin/shell b/assembly/src/main/filtered-resources/unix/bin/shell
index d5c9e9d..327b505 100644
--- a/assembly/src/main/filtered-resources/unix/bin/shell
+++ b/assembly/src/main/filtered-resources/unix/bin/shell
@@ -48,7 +48,7 @@
 fi
 
 warn() {
-    echo "${PROGNAME}: $*"
+    echo "${PROGNAME}: $*" >&2
 }
 
 die() {
diff --git a/assembly/src/main/filtered-resources/win/bin/shell.bat b/assembly/src/main/filtered-resources/win/bin/shell.bat
index 8501a50..1a41ef6 100644
--- a/assembly/src/main/filtered-resources/win/bin/shell.bat
+++ b/assembly/src/main/filtered-resources/win/bin/shell.bat
@@ -48,7 +48,7 @@
 goto BEGIN
 
 :warn
-    echo %PROGNAME%: %*
+    echo %PROGNAME%: %* >&2
 goto :EOF
 
 :BEGIN