diff --git a/Makefile.dkms b/Makefile.dkms
index 3a06762..b7c0d15 100644
--- a/Makefile.dkms
+++ b/Makefile.dkms
@@ -13,12 +13,12 @@ src_install:
 	sed 's/#MODULE_VERSION#/$(modver)/' dkms/dkms.conf > '$(DKMS_DEST)/dkms.conf'
 
 build: src_install
-	$(DKMS) build 'bbswitch/$(modver)'
+	$(DKMS) build -m bbswitch -v $(modver)
 
 install: build
-	$(DKMS) install 'bbswitch/$(modver)'
+	$(DKMS) install -m bbswitch -v $(modver)
 
 uninstall:
-	$(DKMS) remove bbswitch/$(modver) --all
+	$(DKMS) remove -m bbswitch -v $(modver) --all
 
 .PHONY: all src_install build install uninstall
diff --git a/NEWS b/NEWS
index 2f08c50..71252fd 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,13 @@
+* Improved compatibility with older DKMS versions.
+
+Version 0.4.2 - 26 April 2012
+
+* Fixed a documentation error on unload_state.
+* Added Makefile.dkms and documentation for easier installation using DKMS.
+* Make /proc/acpi/bbswitch world-writable
+* Fix NULL pointer dereference when reporting a failure during ACPI method
+  evaluation.
+
 Version 0.4.1 - 16 January 2012
 
 * Corrected a small error that yielded an confusing error message "The discrete
diff --git a/README.md b/README.md
index c282a34..c740ae9 100644
--- a/README.md
+++ b/README.md
@@ -40,8 +40,8 @@ DKMS support
 
 If you have DKMS installed, you can install bbswitch in such a way that it
 survives kernel upgrades. It is recommended to remove older versions of bbswitch
-by running `dkms remove bbswitch/OLDVERSION --all` as root. To install the new
-version, simply run:
+by running `dkms remove -m bbswitch -v OLDVERSION --all` as root. To install
+the new version, simply run:
 
     # make -f Makefile.dkms
 
@@ -116,7 +116,7 @@ The module has some options that control the behavior on loading and unloading:
 `load_state` and `unload_state`. Valid values are `-1`, `0` and `1` meaning "do
 not change the card state", "turn the card off" and "turn the card on"
 respectively. For example, if you want to have `bbswitch` disable the card
-immediately when loading the module while disabling the card on unload, load the
+immediately when loading the module while enabling the card on unload, load the
 module with:
 
     # modprobe bbswitch load_state=0 unload_state=1
diff --git a/bbswitch.c b/bbswitch.c
index aa0f2a5..ca79e0d 100644
--- a/bbswitch.c
+++ b/bbswitch.c
@@ -16,7 +16,7 @@
 #include <linux/suspend.h>
 #include <linux/seq_file.h>
 
-#define BBSWITCH_VERSION "0.4.1"
+#define BBSWITCH_VERSION "0.4.2"
 
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Toggle the discrete graphics card");
@@ -71,12 +71,11 @@ static struct notifier_block nb;
 /* whether the card was off before suspend or not; on: 0, off: 1 */
 int dis_before_suspend_disabled;
 
-static char *buffer_to_string(const char buffer[], char *target) {
+static char *buffer_to_string(const char *buffer, size_t n, char *target) {
     int i;
-    for (i=0; i<sizeof(buffer); i++) {
-        sprintf(target + i * 5, "%02X,", buffer[i]);
+    for (i=0; i<n; i++) {
+        snprintf(target + i * 5, 5 * (n - i), "0x%02X,", buffer ? buffer[i] & 0xFF : 0);
     }
-    target[sizeof(buffer) * 5] = '\0';
     return target;
 }
 
@@ -112,12 +111,13 @@ static int acpi_call_dsm(acpi_handle handle, const char muid[16], int revid,
 
     err = acpi_evaluate_object(handle, "_DSM", &input, &output);
     if (err) {
-        char tmp[5 * max(sizeof(muid), sizeof(args))];
+        char muid_str[5 * 16];
+        char args_str[5 * 4];
 
-        printk(KERN_WARNING "bbswitch: failed to evaluate _DSM {%s} %X %X"
+        printk(KERN_WARNING "bbswitch: failed to evaluate _DSM {%s} 0x%X 0x%X"
             " {%s}: %s\n",
-            buffer_to_string(muid, tmp), revid, func,
-            buffer_to_string(args, tmp), acpi_format_exception(err));
+            buffer_to_string(muid, 16, muid_str), revid, func,
+            buffer_to_string(args,  4, args_str), acpi_format_exception(err));
         return err;
     }