diff --git a/compat/poll/poll.c b/compat/poll/poll.c
index b622982b534eea..16a6ccc4619f27 100644
--- a/compat/poll/poll.c
+++ b/compat/poll/poll.c
@@ -149,7 +149,7 @@ win32_compute_revents (HANDLE h, int *p_sought)
     case FILE_TYPE_PIPE:
       if (!once_only)
 	{
-	  NtQueryInformationFile = (PNtQueryInformationFile)
+	  NtQueryInformationFile = (PNtQueryInformationFile)(void *)
 	    GetProcAddress (GetModuleHandleA ("ntdll.dll"),
 			    "NtQueryInformationFile");
 	  once_only = TRUE;
diff --git a/compat/win32/exit-process.h b/compat/win32/exit-process.h
index 88e3bbc83c499e..5aacf3715005e5 100644
--- a/compat/win32/exit-process.h
+++ b/compat/win32/exit-process.h
@@ -130,7 +130,7 @@ static int exit_process(HANDLE process, int exit_code)
 			HINSTANCE kernel32 = GetModuleHandleA("kernel32");
 			if (!kernel32)
 				die("BUG: cannot find kernel32");
-			exit_process_address = (LPTHREAD_START_ROUTINE)
+			exit_process_address = (LPTHREAD_START_ROUTINE)(void *)
 				GetProcAddress(kernel32, "ExitProcess");
 			initialized = 1;
 		}
diff --git a/kwset.c b/kwset.c
index 4fb6455acaf129..efc2ff41bc361a 100644
--- a/kwset.c
+++ b/kwset.c
@@ -38,7 +38,13 @@
 #include "compat/obstack.h"
 
 #define NCHAR (UCHAR_MAX + 1)
-#define obstack_chunk_alloc xmalloc
+/* adapter for `xmalloc()`, which takes `size_t`, not `long` */
+static void *obstack_chunk_alloc(long size)
+{
+	if (size < 0)
+		BUG("Cannot allocate a negative amount: %ld", size);
+	return xmalloc(size);
+}
 #define obstack_chunk_free free
 
 #define U(c) ((unsigned char) (c))