diff --git a/lib/libspl/include/os/windows/unistd.h b/lib/libspl/include/os/windows/unistd.h
index 868e2e071ac9..81588f64d7fc 100644
--- a/lib/libspl/include/os/windows/unistd.h
+++ b/lib/libspl/include/os/windows/unistd.h
@@ -63,7 +63,9 @@ extern size_t strlcpy(register char *s, register const char *t,
 extern size_t strlcat(register char *s, register const char *t,
     register size_t n);
 
-extern ssize_t getline(char **linep, size_t *linecapp, FILE *stream);
+extern ssize_t getline_impl(char **linep, size_t *linecapp, FILE *stream,
+    boolean_t internal);
+#define	getline(L, C, S) getline_impl((L), (C), (S), FALSE)
 
 // int pread_win(HANDLE h, void *buf, size_t nbyte, off_t offset);
 extern int pipe(int fildes[2]);
diff --git a/lib/libspl/include/os/windows/wfunopen.h b/lib/libspl/include/os/windows/wfunopen.h
index c58cf6b62ea7..d04b60794982 100644
--- a/lib/libspl/include/os/windows/wfunopen.h
+++ b/lib/libspl/include/os/windows/wfunopen.h
@@ -122,10 +122,12 @@ static inline ssize_t wosix_getline(char **linep, size_t *linecap, FILE *f)
 	fakeFILE *fFILE = (fakeFILE *)f;
 	int result;
 
-	if (fFILE->realFILE)
+	if (f == stdin)
+		result = getline_impl(linep, linecap, f, FALSE);
+	else if (fFILE->realFILE)
 		result = getline(linep, linecap, fFILE->realFILE);
 	else
-		result = fFILE->readfn(fFILE->cookie, *linep, *linecap);
+		result = getline_impl(linep, linecap, fFILE, TRUE);
 
 	return (result);
 }
diff --git a/lib/libspl/os/windows/posix.c b/lib/libspl/os/windows/posix.c
index 63f42a197eac..9eba2b95a9ce 100644
--- a/lib/libspl/os/windows/posix.c
+++ b/lib/libspl/os/windows/posix.c
@@ -40,6 +40,7 @@
 #include <langinfo.h>
 #include <os/windows/zfs/sys/zfs_ioctl_compat.h>
 #include <sys/mman.h>
+#include <wfunopen.h>
 
 /* Magic instruction to compiler to add library */
 #pragma comment(lib, "ws2_32.lib")
@@ -889,17 +890,21 @@ console_echo(boolean_t willecho)
 // Not really getline, just used for password input in libzfs_crypto.c
 #define	MAX_GETLINE 128
 ssize_t
-getline(char **linep, size_t *linecapp,
-    FILE *stream)
+getline_impl(char **linep, size_t *linecapp,
+    FILE *stream, boolean_t internal)
 {
 	static char getpassbuf[MAX_GETLINE + 1];
 	size_t i = 0;
+	fakeFILE *fFILE = (fakeFILE *)stream;
 
 	console_echo(FALSE);
 
 	int c;
 	for (;;) {
-		c = getc(stream);
+		if (internal)
+			fFILE->readfn(fFILE->cookie, &c, 1);
+		else
+			c = getc(stream);
 		if ((c == '\r') || (c == '\n')) {
 			getpassbuf[i] = '\0';
 			break;