diff --git a/sys/contrib/dev/acpica/components/utilities/utdelete.c b/sys/contrib/dev/acpica/components/utilities/utdelete.c
index 9b3b7d3..a6750ed 100644
--- a/sys/contrib/dev/acpica/components/utilities/utdelete.c
+++ b/sys/contrib/dev/acpica/components/utilities/utdelete.c
@@ -415,6 +415,8 @@ AcpiUtUpdateRefCount (
         return;
     }
 
+    (void) AcpiUtAcquireMutex (ACPI_MTX_REFCOUNTS);
+
     Count = Object->Common.ReferenceCount;
     NewCount = Count;
 
@@ -427,6 +429,7 @@ AcpiUtUpdateRefCount (
 
         NewCount++;
         Object->Common.ReferenceCount = NewCount;
+	(void) AcpiUtReleaseMutex (ACPI_MTX_REFCOUNTS);
 
         ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
             "Obj %p Refs=%X, [Incremented]\n",
@@ -437,11 +440,11 @@ AcpiUtUpdateRefCount (
 
         if (Count < 1)
         {
-            ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
+            ACPI_ERROR ((AE_INFO,
                 "Obj %p Refs=%X, can't decrement! (Set to 0)\n",
                 Object, NewCount));
-
-            NewCount = 0;
+	    (void) AcpiUtReleaseMutex (ACPI_MTX_REFCOUNTS);
+	    break;
         }
         else
         {
@@ -459,6 +462,7 @@ AcpiUtUpdateRefCount (
         }
 
         Object->Common.ReferenceCount = NewCount;
+	(void) AcpiUtReleaseMutex (ACPI_MTX_REFCOUNTS);
         if (NewCount == 0)
         {
             AcpiUtDeleteInternalObj (Object);
@@ -467,16 +471,18 @@ AcpiUtUpdateRefCount (
 
     case REF_FORCE_DELETE:
 
-        ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
+        ACPI_ERROR ((AE_INFO,
             "Obj %p Refs=%X, Force delete! (Set to 0)\n", Object, Count));
 
         NewCount = 0;
         Object->Common.ReferenceCount = NewCount;
+	(void) AcpiUtReleaseMutex (ACPI_MTX_REFCOUNTS);
         AcpiUtDeleteInternalObj (Object);
         break;
 
     default:
 
+	(void) AcpiUtReleaseMutex (ACPI_MTX_REFCOUNTS);
         ACPI_ERROR ((AE_INFO, "Unknown action (0x%X)", Action));
         break;
     }
diff --git a/sys/contrib/dev/acpica/include/aclocal.h b/sys/contrib/dev/acpica/include/aclocal.h
index 8a35147..1c4d0ec 100644
--- a/sys/contrib/dev/acpica/include/aclocal.h
+++ b/sys/contrib/dev/acpica/include/aclocal.h
@@ -89,8 +89,9 @@ union acpi_parse_object;
 #define ACPI_MTX_MEMORY                 5   /* Debug memory tracking lists */
 #define ACPI_MTX_DEBUG_CMD_COMPLETE     6   /* AML debugger */
 #define ACPI_MTX_DEBUG_CMD_READY        7   /* AML debugger */
+#define ACPI_MTX_REFCOUNTS              8   /* ACPI object reference counts */
 
-#define ACPI_MAX_MUTEX                  7
+#define ACPI_MAX_MUTEX                  8
 #define ACPI_NUM_MUTEX                  ACPI_MAX_MUTEX+1