diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7afe2f4..bc815b5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,8 +8,9 @@ option(ENABLE_CLANG_TIDY "Run clang-tidy during compilation" OFF)
 include(FetchContent)
 
 FetchContent_Declare(GKey GIT_REPOSITORY https://github.com/chrisbazley/GKeyLib.git GIT_TAG main)
+FetchContent_Declare(CBUtil GIT_REPOSITORY https://github.com/chrisbazley/CBUtilLib.git GIT_TAG main)
 
-FetchContent_MakeAvailable(GKey)
+FetchContent_MakeAvailable(GKey CBUtil)
 
 if(USE_OPTIONAL)
     if(NOT CMAKE_C_COMPILER_ID MATCHES "Clang|AppleClang")
@@ -80,20 +81,12 @@ file(GLOB PUBLIC_HEADERS "*.h")
 file(GLOB PRIVATE_HEADERS "Internal/*.h")
 
 add_library(Stream STATIC ${SOURCES} ${PUBLIC_HEADERS} ${PRIVATE_HEADERS})
-target_link_libraries(Stream PRIVATE GKey)
+target_link_libraries(Stream PRIVATE GKey CBUtil)
 set_target_properties(Stream PROPERTIES
     PUBLIC_HEADER "${PUBLIC_HEADERS}"
     DEBUG_POSTFIX "dbg"
 )
 
-if(USE_OPTIONAL)
-    FetchContent_Declare(CBUtil GIT_REPOSITORY https://github.com/chrisbazley/CBUtilLib.git GIT_TAG main)
-
-    FetchContent_MakeAvailable(CBUtil)
-
-    target_link_libraries(Stream PRIVATE CBUtil)
-endif()
-
 target_include_directories(Stream PUBLIC .)
 
 target_compile_definitions(Stream PRIVATE
diff --git a/Internal/StreamMisc.h b/Internal/StreamMisc.h
index 48e053b..5c1e87c 100644
--- a/Internal/StreamMisc.h
+++ b/Internal/StreamMisc.h
@@ -22,15 +22,18 @@
   CJB: 04-Nov-18: Created this source file.
   CJB: 26-Aug-19: Now requires "PseudoFlex.h" too.
   CJB: 07-Jun-20: Added support for verbose debugging output.
-  CJB: 22-Sep-26: Remove a redundant include of PseudoIO.h because fortify.h
-                  already enables standard I/O interception.
   CJB: 09-Apr-25: Dogfooding the _Optional qualifier.
   CJB: 15-Jun-26: Send the debug log to stderr not stdout.
+  CJB: 22-Sep-26: Remove a redundant include of PseudoIO.h because fortify.h
+                  already enables standard I/O interception.
+  CJB: 22-Sep-26: Use common macro definitions from CBUtilLib.
 */
 
 #ifndef StreamMisc_h
 #define StreamMisc_h
 
+#include "MacroUtils.h"
+
 #ifdef FORTIFY
 #include "fortify.h"
 #endif
@@ -65,6 +68,4 @@
 #define _Optional
 #endif
 
-#define NOT_USED(x) ((void)(x))
-
 #endif /* StreamMisc_h */
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 84beeec..d778bfd 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -2,10 +2,5 @@ file(GLOB SOURCES "*.c")
 file(GLOB PRIVATE_HEADERS "*.h")
 
 add_executable(StreamTests ${SOURCES} ${PRIVATE_HEADERS})
-target_link_libraries(StreamTests PRIVATE Stream)
-target_link_libraries(StreamTests PRIVATE GKey)
+target_link_libraries(StreamTests PRIVATE Stream GKey CBUtil)
 add_test(NAME "StreamTests" COMMAND StreamTests)
-
-if(USE_OPTIONAL)
-    target_link_libraries(StreamTests PRIVATE CBUtil)
-endif()
diff --git a/tests/Tests.h b/tests/Tests.h
index 6494507..4ae186b 100644
--- a/tests/Tests.h
+++ b/tests/Tests.h
@@ -22,6 +22,8 @@
 
 #undef NDEBUG
 
+#include "MacroUtils.h"
+
 #ifdef FORTIFY
 #include "fortify.h"
 #else
@@ -51,9 +53,6 @@
 #define _Optional
 #endif
 
-#define NOT_USED(x) ((void)(x))
-#define ARRAY_SIZE(array) (sizeof(array) / sizeof((array)[0]))
-
 extern void Reader_tests(void);
 extern void ReaderNull_tests(void);
 extern void Writer_tests(void);