diff --git a/src/proc/engine/buffhandle.hpp b/src/proc/engine/buffhandle.hpp
index affbf8dd6..eb87ffec2 100644
--- a/src/proc/engine/buffhandle.hpp
+++ b/src/proc/engine/buffhandle.hpp
@@ -52,6 +52,9 @@
 
 namespace engine {
   
+  namespace error = lumiera::error;
+  using error::LUMIERA_ERROR_LIFECYCLE;
+  
   typedef size_t HashVal;           ////////////TICKET #722
   
   class BuffHandle;
@@ -227,7 +230,9 @@ namespace engine {
   BU&
   BuffHandle::accessAs()
   {
-    REQUIRE (pBuffer_);
+    if (!pBuffer_)
+      throw error::Logic ("buffer not (yet) locked for access by clients"
+                         , LUMIERA_ERROR_LIFECYCLE);
     return *reinterpret_cast<BU*> (pBuffer_);
   }
   
diff --git a/tests/components/proc/engine/buffer-provider-protocol-test.cpp b/tests/components/proc/engine/buffer-provider-protocol-test.cpp
index fdfba1e67..6732668b6 100644
--- a/tests/components/proc/engine/buffer-provider-protocol-test.cpp
+++ b/tests/components/proc/engine/buffer-provider-protocol-test.cpp
@@ -76,7 +76,6 @@ namespace test  {
       virtual void
       run (Arg) 
         {
-          UNIMPLEMENTED ("build a diagnostic buffer provider and perform a full lifecycle");
           verifySimpleUsage();
           verifyStandardCase();
         }
@@ -93,10 +92,10 @@ namespace test  {
           BuffHandle buff = provider.lockBufferFor<TestFrame>();
           CHECK (buff.isValid());
           CHECK (sizeof(TestFrame) <= buff.size());
-          buff.create<TestFrame>() = testData(0);
+          buff.accessAs<TestFrame>() = testData(0);
           
-          TestFrame& storage = buff.accessAs<TestFrame>();
-          CHECK (testData(0) == storage);
+          TestFrame& content = buff.accessAs<TestFrame>();
+          CHECK (testData(0) == content);
           
           buff.release();
           CHECK (!buff.isValid());