diff --git a/lib/guestfs-internal.h b/lib/guestfs-internal.h
index 073e665d3..290d1f948 100644
--- a/lib/guestfs-internal.h
+++ b/lib/guestfs-internal.h
@@ -797,7 +797,7 @@ extern struct version guestfs_int_qemu_version (guestfs_h *g, struct qemu_data *
 extern int guestfs_int_qemu_supports_device (guestfs_h *g, const struct qemu_data *, const char *device_name);
 extern bool guestfs_int_platform_has_kvm (guestfs_h *g, const struct qemu_data *data);
 extern char *guestfs_int_drive_source_qemu_param (guestfs_h *g, const struct drive_source *src);
-extern bool guestfs_int_discard_possible (guestfs_h *g, struct drive *drv, const struct version *qemu_version);
+extern bool guestfs_int_discard_possible (guestfs_h *g, struct drive *drv);
 extern char *guestfs_int_qemu_escape_param (guestfs_h *g, const char *param);
 extern void guestfs_int_free_qemu_data (struct qemu_data *);
 
diff --git a/lib/launch-direct.c b/lib/launch-direct.c
index 6b495dfa1..65541dbe7 100644
--- a/lib/launch-direct.c
+++ b/lib/launch-direct.c
@@ -221,21 +221,15 @@ add_drive_standard_params (guestfs_h *g, struct backend_direct_data *data,
     switch (drv->discard) {
     case discard_disable:
       /* Since the default is always discard=ignore, don't specify it
-       * on the command line.  This also avoids unnecessary breakage
-       * with qemu < 1.5 which didn't have the option at all.
+       * on the command line.
        */
       break;
     case discard_enable:
-      if (!guestfs_int_discard_possible (g, drv, &data->qemu_version))
+      if (!guestfs_int_discard_possible (g, drv))
         return -1;
       /*FALLTHROUGH*/
     case discard_besteffort:
-      /* I believe from reading the code that this is always safe as
-       * long as qemu >= 1.5.
-       */
-      if (guestfs_int_version_ge (&data->qemu_version, 1, 5, 0))
-        append_list ("discard=unmap");
-      break;
+      append_list ("discard=unmap");
     }
   }
   else {
diff --git a/lib/launch-libvirt.c b/lib/launch-libvirt.c
index c690a444a..e02a86f89 100644
--- a/lib/launch-libvirt.c
+++ b/lib/launch-libvirt.c
@@ -1651,16 +1651,11 @@ construct_libvirt_xml_disk_driver_qemu (guestfs_h *g,
      */
     break;
   case discard_enable:
-    if (!guestfs_int_discard_possible (g, drv, &data->qemu_version))
+    if (!guestfs_int_discard_possible (g, drv))
       return -1;
     /*FALLTHROUGH*/
   case discard_besteffort:
-    /* I believe from reading the code that this is always safe as
-     * long as qemu >= 1.5.
-     */
-    if (guestfs_int_version_ge (&data->qemu_version, 1, 5, 0))
-      discard_unmap = true;
-    break;
+    discard_unmap = true;
   }
 
   start_element ("driver") {
diff --git a/lib/qemu.c b/lib/qemu.c
index ac8bf678b..c96d66bda 100644
--- a/lib/qemu.c
+++ b/lib/qemu.c
@@ -820,31 +820,15 @@ guestfs_int_drive_source_qemu_param (guestfs_h *g,
 }
 
 /**
- * Test if discard is both supported by qemu AND possible with the
- * underlying file or device.  This returns C<1> if discard is
- * possible.  It returns C<0> if not possible and sets the error to
- * the reason why.
+ * Test if discard is possible with the underlying file or device.
+ * This returns C<1> if discard is possible.  It returns C<0> if not
+ * possible and sets the error to the reason why.
  *
  * This function is called when the user set C<discard == "enable">.
  */
 bool
-guestfs_int_discard_possible (guestfs_h *g, struct drive *drv,
-			      const struct version *qemu_version)
+guestfs_int_discard_possible (guestfs_h *g, struct drive *drv)
 {
-  /* qemu >= 1.5.  This was the first version that supported the
-   * discard option on -drive at all.
-   */
-  bool qemu15 = guestfs_int_version_ge (qemu_version, 1, 5, 0);
-  /* qemu >= 1.6.  This was the first version that supported unmap on
-   * qcow2 backing files.
-   */
-  bool qemu16 = guestfs_int_version_ge (qemu_version, 1, 6, 0);
-
-  if (!qemu15)
-    NOT_SUPPORTED (g, false,
-                   _("discard cannot be enabled on this drive: "
-                     "qemu < 1.5"));
-
   /* If it's an overlay, discard is not possible (on the underlying
    * file).  This has probably been caught earlier since we already
    * checked that the drive is !readonly.  Nevertheless ...
@@ -861,17 +845,11 @@ guestfs_int_discard_possible (guestfs_h *g, struct drive *drv,
                    _("discard cannot be enabled on this drive: "
                      "you have to specify the format of the file"));
   }
-  else if (STREQ (drv->src.format, "raw"))
+  else if (STREQ (drv->src.format, "raw") || STREQ (drv->src.format, "qcow2"))
     /* OK */ ;
-  else if (STREQ (drv->src.format, "qcow2")) {
-    if (!qemu16)
-      NOT_SUPPORTED (g, false,
-                     _("discard cannot be enabled on this drive: "
-                       "qemu < 1.6 cannot do discard on qcow2 files"));
-  }
   else {
-    /* It's possible in future other formats will support discard, but
-     * currently (qemu 1.7) none of them do.
+    /* It's possible other formats support discard, but we can enable
+     * them on a case-by-case basis.
      */
     NOT_SUPPORTED (g, false,
                    _("discard cannot be enabled on this drive: "