diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5d2a364d1..8dee004b0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -44,7 +44,7 @@ include(GNUInstallDirs)
 
 # needed packages
 
-#Allow users to specify location of Zlib, 
+#Allow users to specify location of Zlib,
 # Useful if zlib is being built alongside this as a sub-project
 option(PNG_BUILD_ZLIB "Custom zlib Location, else find_package is used" OFF)
 
@@ -98,7 +98,7 @@ if(${CMAKE_SYSTEM_PROCESSOR} MATCHES "^arm" OR
       arm/arm_init.c
       arm/filter_neon.S
       arm/filter_neon_intrinsics.c)
-      
+
     if(${PNG_ARM_NEON} STREQUAL "on")
       add_definitions(-DPNG_ARM_NEON_OPT=2)
     elseif(${PNG_ARM_NEON} STREQUAL "check")
@@ -127,13 +127,13 @@ if(${CMAKE_SYSTEM_PROCESSOR} MATCHES "^powerpc*" OR
     set(libpng_powerpc_sources
       powerpc/powerpc_init.c
       powerpc/filter_vsx_intrinsics.c)
-      
+
     if(${PNG_POWERPC_VSX} STREQUAL "on")
       add_definitions(-DPNG_POWERPC_VSX_OPT=2)
     elseif(${PNG_POWERPC_VSX} STREQUAL "check")
       add_definitions(-DPNG_POWERPC_VSX_CHECK_SUPPORTED)
       message(WARNING
-        " Please check contrib/powerpc/README file for the list of supported OSes.")
+      "[PNG_POWERPC_VSX==check] Please check contrib/powerpc/README file for the list of supported OSes.")
     endif()
   else()
     add_definitions(-DPNG_POWERPC_VSX_OPT=0)
@@ -875,4 +875,3 @@ endif()
 # to create msvc import lib for mingw compiled shared lib
 # pexports libpng.dll > libpng.def
 # lib /def:libpng.def /machine:x86
-