diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index a11c630a7b1d..90b3ef214097 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -263,7 +263,11 @@ static bool mmap_frag(abi_ulong real_start, abi_ulong start, abi_ulong last,
         void *p = mmap(host_start, qemu_host_page_size,
                        target_to_host_prot(prot),
                        flags | MAP_ANONYMOUS, -1, 0);
-        if (p == MAP_FAILED) {
+        if (p != host_start) {
+            if (p != MAP_FAILED) {
+                munmap(p, qemu_host_page_size);
+                errno = EEXIST;
+            }
             return false;
         }
         prot_old = prot;
@@ -687,17 +691,25 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot,
 
         /* map the middle (easier) */
         if (real_start < real_last) {
-            void *p;
+            void *p, *want_p;
             off_t offset1;
+            size_t len1;
 
             if (flags & MAP_ANONYMOUS) {
                 offset1 = 0;
             } else {
                 offset1 = offset + real_start - start;
             }
-            p = mmap(g2h_untagged(real_start), real_last - real_start + 1,
-                     target_to_host_prot(target_prot), flags, fd, offset1);
-            if (p == MAP_FAILED) {
+            len1 = real_last - real_start + 1;
+            want_p = g2h_untagged(real_start);
+
+            p = mmap(want_p, len1, target_to_host_prot(target_prot),
+                     flags, fd, offset1);
+            if (p != want_p) {
+                if (p != MAP_FAILED) {
+                    munmap(p, len1);
+                    errno = EEXIST;
+                }
                 goto fail;
             }
             passthrough_start = real_start;