diff --git a/src/corelib/ipc/qsharedmemory.cpp b/src/corelib/ipc/qsharedmemory.cpp
index 02761c0263..e1ce735f89 100644
--- a/src/corelib/ipc/qsharedmemory.cpp
+++ b/src/corelib/ipc/qsharedmemory.cpp
@@ -12,6 +12,7 @@
 #ifdef Q_OS_WIN
 #  include <qt_windows.h>
 #endif
+#include <errno.h>
 
 #ifndef MAX_PATH
 #  define MAX_PATH PATH_MAX
diff --git a/src/corelib/ipc/qsystemsemaphore.cpp b/src/corelib/ipc/qsystemsemaphore.cpp
index 4c24ef6043..24f4789f97 100644
--- a/src/corelib/ipc/qsystemsemaphore.cpp
+++ b/src/corelib/ipc/qsystemsemaphore.cpp
@@ -6,6 +6,7 @@
 
 #if QT_CONFIG(systemsemaphore)
 #include <QtCore/q20memory.h>
+#include <errno.h>
 
 QT_BEGIN_NAMESPACE