diff --git a/src/plugins/meson.build b/src/plugins/meson.build
index 45abe88eb..e8aceb4e9 100644
--- a/src/plugins/meson.build
+++ b/src/plugins/meson.build
@@ -314,6 +314,10 @@ if get_option('plugin-windowmon')
     config_h.set('ENABLE_PLUGIN_WINDOWMON', 1)
 endif
 
+if get_option('disable-output-buffering')
+    config_h.set('DISABLE_OUTPUT_BUFFERING', 1)
+endif
+
 summary({
     'syscalls': get_option('plugin-syscalls'),
     'poolmon': get_option('plugin-poolmon'),
diff --git a/src/plugins/output_format/ostream.h b/src/plugins/output_format/ostream.h
index e6b316cf3..3af1c0eec 100644
--- a/src/plugins/output_format/ostream.h
+++ b/src/plugins/output_format/ostream.h
@@ -106,6 +106,10 @@
 #define PLUGINS_OUTPUT_FORMAT_OSTREAM_H
 #pragma once
 
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif /* HAVE_CONFIG_H */
+
 #include <iostream>
 
 namespace fmt