diff --git a/doc/xml/release.xml b/doc/xml/release.xml
index 41af42e02..ec5f0833e 100644
--- a/doc/xml/release.xml
+++ b/doc/xml/release.xml
@@ -84,7 +84,7 @@
                     </release-item>
 
                     <release-item>
-                        <p>Add <code>ASSERT_DEBUG()</code> macro for debugging and replace all current <code>assert()</code> calls except in tests that can't use the debug code.</p>
+                        <p>Improve debugging.  Add <code>ASSERT_DEBUG()</code> macro for debugging and replace all current <code>assert()</code> calls except in tests that can't use the debug code.  Replace remaining NDEBUG blocks with the more granular DEBUG_UNIT.  Remove some debug <code>memset()</code> calls in <code>MemContext</code> since valgrind is more useful for these checks.</p>
                     </release-item>
 
                     <release-item>
diff --git a/src/common/debug.h b/src/common/debug.h
index c97762a1b..1f8499dfb 100644
--- a/src/common/debug.h
+++ b/src/common/debug.h
@@ -15,6 +15,9 @@ NDEBUG indicates to C library routines that debugging is off -- set a more reada
 
 /***********************************************************************************************************************************
 Assert Macros
+
+Used for assertions that should only be run when debugging.  Ideal for conditions that are not likely to happen in production but
+could occur during development.
 ***********************************************************************************************************************************/
 #ifdef DEBUG
     #define ASSERT_DEBUG(condition)                                                                                                \
@@ -26,4 +29,14 @@ Assert Macros
     #define ASSERT_DEBUG(condition)
 #endif
 
+/***********************************************************************************************************************************
+Extern variables that are needed for unit testing
+***********************************************************************************************************************************/
+#ifdef DEBUG_UNIT
+    #define DEBUG_UNIT_EXTERN
+#else
+    #define DEBUG_UNIT_EXTERN                                                                                                      \
+        static
+#endif
+
 #endif
diff --git a/src/common/log.c b/src/common/log.c
index 592be9bb2..e6bdd20f5 100644
--- a/src/common/log.c
+++ b/src/common/log.c
@@ -18,20 +18,20 @@ Log Handler
 Module variables
 ***********************************************************************************************************************************/
 // Log levels
-LogLevel logLevelStdOut = logLevelError;
-LogLevel logLevelStdErr = logLevelError;
-LogLevel logLevelFile = logLevelOff;
+DEBUG_UNIT_EXTERN LogLevel logLevelStdOut = logLevelError;
+DEBUG_UNIT_EXTERN LogLevel logLevelStdErr = logLevelError;
+DEBUG_UNIT_EXTERN LogLevel logLevelFile = logLevelOff;
 
 // Log file handles
-int logHandleStdOut = STDOUT_FILENO;
-int logHandleStdErr = STDERR_FILENO;
-int logHandleFile = -1;
+DEBUG_UNIT_EXTERN int logHandleStdOut = STDOUT_FILENO;
+DEBUG_UNIT_EXTERN int logHandleStdErr = STDERR_FILENO;
+DEBUG_UNIT_EXTERN int logHandleFile = -1;
 
 // Has the log file banner been written yet?
-bool logFileBanner = false;
+static bool logFileBanner = false;
 
 // Is the timestamp printed in the log?
-bool logTimestamp = false;
+static bool logTimestamp = false;
 
 /***********************************************************************************************************************************
 Debug Asserts
diff --git a/src/common/log.h b/src/common/log.h
index 70f116f21..c5b6e8824 100644
--- a/src/common/log.h
+++ b/src/common/log.h
@@ -23,9 +23,9 @@ typedef enum
 } LogLevel;
 
 /***********************************************************************************************************************************
-Expose internal data for debugging/testing
+Expose internal data for unit testing/debugging
 ***********************************************************************************************************************************/
-#ifndef NDEBUG
+#ifdef DEBUG_UNIT
     extern LogLevel logLevelStdOut;
     extern LogLevel logLevelStdErr;
     extern LogLevel logLevelFile;
@@ -33,8 +33,6 @@ Expose internal data for debugging/testing
     extern int logHandleStdOut;
     extern int logHandleStdErr;
     extern int logHandleFile;
-
-    extern bool logTimestamp;
 #endif
 
 /***********************************************************************************************************************************
diff --git a/src/common/memContext.c b/src/common/memContext.c
index 73991e120..b8d401fc6 100644
--- a/src/common/memContext.c
+++ b/src/common/memContext.c
@@ -325,11 +325,6 @@ memFree(void *buffer)
     // Find the allocation
     MemContextAlloc *alloc = &(memContextCurrent()->allocList[memFind(buffer)]);
 
-    // DEBUG: zero buffer to make it more obvious that it was freed if there are still references to it
-    #ifndef NDEBUG
-        memset(alloc->buffer, 0, alloc->size);
-    #endif
-
     // Free the buffer
     memFreeInternal(alloc->buffer);
     alloc->active = false;
@@ -433,14 +428,7 @@ memContextFree(MemContext *this)
             MemContextAlloc *alloc = &(this->allocList[allocIdx]);
 
             if (alloc->active)
-            {
-                // DEBUG: zero buffer to make it more obvious that it was freed if there are still references to it
-                #ifndef NDEBUG
-                    memset(alloc->buffer, 0, alloc->size);
-                #endif
-
                 memFreeInternal(alloc->buffer);
-            }
         }
 
         memFreeInternal(this->allocList);
diff --git a/test/lib/pgBackRestTest/Common/JobTest.pm b/test/lib/pgBackRestTest/Common/JobTest.pm
index cc81b6d2f..25f578f53 100644
--- a/test/lib/pgBackRestTest/Common/JobTest.pm
+++ b/test/lib/pgBackRestTest/Common/JobTest.pm
@@ -344,7 +344,7 @@ sub run
                     "       `perl -MExtUtils::Embed -e ccopts`\n" .
                     "LDFLAGS=-lcrypto" . (vmCoverage($self->{oTest}->{&TEST_VM}) ? " -lgcov" : '') .
                         " `perl -MExtUtils::Embed -e ldopts`\n" .
-                    'TESTFLAGS=' . ($self->{oTest}->{&TEST_CDEF} ? "$self->{oTest}->{&TEST_CDEF}" : '') .
+                    'TESTFLAGS=-DDEBUG_UNIT' . ($self->{oTest}->{&TEST_CDEF} ? " $self->{oTest}->{&TEST_CDEF}" : '') .
                     "\n" .
                     "\nSRCS=" . join(' ', @stryCFile) . "\n" .
                     "OBJS=\$(SRCS:.c=.o)\n" .