diff --git a/src/plugins/platforminputcontexts/compose/generator/qtablegenerator.cpp b/src/plugins/platforminputcontexts/compose/generator/qtablegenerator.cpp
index c222b62a36..b5e3aa741e 100644
--- a/src/plugins/platforminputcontexts/compose/generator/qtablegenerator.cpp
+++ b/src/plugins/platforminputcontexts/compose/generator/qtablegenerator.cpp
@@ -55,6 +55,7 @@
 #include <xkbcommon_workaround.h>
 #endif
 
+#include <locale.h> // LC_CTYPE
 #include <string.h> // strchr, strncmp, etc.
 #include <strings.h> // strncasecmp
 
diff --git a/src/plugins/platforms/xcb/qxcbsessionmanager.cpp b/src/plugins/platforms/xcb/qxcbsessionmanager.cpp
index 6abe24b7ab..9d81c8e224 100644
--- a/src/plugins/platforms/xcb/qxcbsessionmanager.cpp
+++ b/src/plugins/platforms/xcb/qxcbsessionmanager.cpp
@@ -48,6 +48,7 @@
 #include <qplatformdefs.h>
 #include <qsocketnotifier.h>
 #include <X11/SM/SMlib.h>
+#include <errno.h> // ERANGE
 
 
 class QSmSocketReceiver : public QObject