diff --git a/CMakeModules/UseCompat.cmake b/CMakeModules/UseCompat.cmake
index ac330e5..753b10d 100644
--- a/CMakeModules/UseCompat.cmake
+++ b/CMakeModules/UseCompat.cmake
@@ -54,6 +54,7 @@
     check_symbol_exists(realpath "stdlib.h" HAVE_REALPATH)
     check_symbol_exists(localtime_r "time.h" HAVE_LOCALTIME_R)
     check_symbol_exists(strptime "time.h" HAVE_STRPTIME)
+    check_symbol_exists(mmap "sys/mman.h" HAVE_MMAP)
 
     unset(CMAKE_REQUIRED_DEFINITIONS)
     unset(CMAKE_REQUIRED_LIBRARIES)
diff --git a/compat/compat.h.in b/compat/compat.h.in
index f8be220..6672fcf 100644
--- a/compat/compat.h.in
+++ b/compat/compat.h.in
@@ -64,6 +64,7 @@
 #cmakedefine HAVE_REALPATH
 #cmakedefine HAVE_LOCALTIME_R
 #cmakedefine HAVE_STRPTIME
+#cmakedefine HAVE_MMAP
 
 #ifndef bswap64
 #define bswap64(val) \
diff --git a/src/common.c b/src/common.c
index fa27588..41e5270 100644
--- a/src/common.c
+++ b/src/common.c
@@ -24,7 +24,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifndef _WIN32
 #include <sys/mman.h>
+#endif
 #include <sys/stat.h>
 #include <unistd.h>
 
@@ -346,6 +348,7 @@
     return len;
 }
 
+#ifdef HAVE_MMAP
 LY_ERR
 ly_mmap(struct ly_ctx *ctx, int fd, size_t *length, void **addr)
 {
@@ -404,6 +407,71 @@
     return LY_SUCCESS;
 }
 
+#else
+
+LY_ERR
+ly_mmap(struct ly_ctx *ctx, int fd, size_t *length, void **addr)
+{
+    struct stat sb;
+    size_t m;
+
+    assert(length);
+    assert(addr);
+    assert(fd >= 0);
+
+    if (fstat(fd, &sb) == -1) {
+        LOGERR(ctx, LY_ESYS, "Failed to stat the file descriptor (%s) for the mmap().", strerror(errno));
+        return LY_ESYS;
+    }
+    if (!S_ISREG(sb.st_mode)) {
+        LOGERR(ctx, LY_EINVAL, "File to mmap() is not a regular file.");
+        return LY_ESYS;
+    }
+    if (!sb.st_size) {
+        *addr = NULL;
+        return LY_SUCCESS;
+    }
+    /* On Windows, the mman-win32 mmap() emulation uses CreateFileMapping and MapViewOfFile, and these functions
+     * do not allow mapping more than "length of file" bytes for PROT_READ. Remapping existing mappings is not allowed, either.
+     * At that point the path of least resistance is just reading the file in as-is. */
+    m = sb.st_size + 1;
+    char *buf = calloc(m, 1);
+
+    if (!buf) {
+        LOGERR(ctx, LY_ESYS, "ly_mmap: malloc() failed (%s).", strerror(errno));
+    }
+    *addr = buf;
+    *length = m;
+
+    lseek(fd, 0, SEEK_SET);
+    ssize_t to_read = m - 1;
+
+    while (to_read > 0) {
+        ssize_t n = read(fd, buf, to_read);
+        if (n == 0) {
+            return LY_SUCCESS;
+        } else if (n < 0) {
+            if (errno == EINTR) {
+                continue; // can I get this on Windows?
+            }
+            LOGERR(ctx, LY_ESYS, "ly_mmap: read() failed (%s).", strerror(errno));
+        }
+        to_read -= n;
+        buf += n;
+    }
+    return LY_SUCCESS;
+}
+
+LY_ERR
+ly_munmap(void *addr, size_t length)
+{
+    (void)length;
+    free(addr);
+    return LY_SUCCESS;
+}
+
+#endif
+
 LY_ERR
 ly_strcat(char **dest, const char *format, ...)
 {