diff --git a/Console/LPT.cpp b/Console/LPT.cpp
index 441fcaa7..e218f865 100644
--- a/Console/LPT.cpp
+++ b/Console/LPT.cpp
@@ -1,4 +1,5 @@
 module;
+#include "winheaders.h"   // HINSTANCE
 #include <string>
 
 module eu07.console.lpt;
diff --git a/Console/PoKeys55.cpp b/Console/PoKeys55.cpp
index d6e3751c..bd4af51d 100644
--- a/Console/PoKeys55.cpp
+++ b/Console/PoKeys55.cpp
@@ -1,4 +1,5 @@
 module;
+#include "winheaders.h"   // HANDLE; setupapi.h happens to pull it in, but say so
 #include <cstdlib>
 #include <string>
 #include <setupapi.h>
diff --git a/extras/piped_proc.cpp b/extras/piped_proc.cpp
index 7fa24717..5723a556 100644
--- a/extras/piped_proc.cpp
+++ b/extras/piped_proc.cpp
@@ -1,4 +1,7 @@
 module;
+#ifdef _WIN32
+#include "winheaders.h"   // the interface has this in its own fragment, which does not cross
+#endif
 #include <array>
 #include <chrono>
 #include <deque>
diff --git a/input/zmq_input.cpp b/input/zmq_input.cpp
index a462bacf..95c96963 100644
--- a/input/zmq_input.cpp
+++ b/input/zmq_input.cpp
@@ -1,4 +1,5 @@
 module;
+#include "winheaders.h"   // SYSTEMTIME
 #include <array>
 #include <deque>
 #include <limits>
diff --git a/windows.cpp b/windows.cpp
index d8e237ce..173f3f04 100644
--- a/windows.cpp
+++ b/windows.cpp
@@ -1,3 +1,4 @@
+#include "winheaders.h"
 #include "utilities/utilities_macros.h"
 #include <array>
 #include <chrono>