diff --git a/libraries/avr-libcpp/CMakeLists.txt b/libraries/avr-libcpp/CMakeLists.txt
index d089b7b..497d0fe 100644
--- a/libraries/avr-libcpp/CMakeLists.txt
+++ b/libraries/avr-libcpp/CMakeLists.txt
@@ -18,7 +18,7 @@
 add_library( avr-libcpp STATIC )
 
 target_compile_definitions( avr-libcpp
-    PUBLIC $<IF:$<BOOL:${AVRLIBCPP_SUPPRESS_SFR_MACROS}>,AVRLIBCPP_SUPPRESS_SFR_MACROS,>
+    PUBLIC AVRLIBCPP_SUPPRESS_SFR_MACROS=$<IF:$<BOOL:${AVRLIBCPP_SUPPRESS_SFR_MACROS}>,1,0>
     )
 
 target_include_directories( avr-libcpp
diff --git a/libraries/avr-libcpp/include/avr-libcpp/suppress_sfr_macros/atmega2560.h b/libraries/avr-libcpp/include/avr-libcpp/suppress_sfr_macros/atmega2560.h
index 4b1bb18..32bb948 100644
--- a/libraries/avr-libcpp/include/avr-libcpp/suppress_sfr_macros/atmega2560.h
+++ b/libraries/avr-libcpp/include/avr-libcpp/suppress_sfr_macros/atmega2560.h
@@ -26,7 +26,7 @@
 #include <avr/io.h>
 
 #ifdef __AVR_ATmega2560__
-#ifdef AVRLIBCPP_SUPPRESS_SFR_MACROS
+#if AVRLIBCPP_SUPPRESS_SFR_MACROS
 
 #ifdef ACBG
 #undef ACBG
diff --git a/libraries/avr-libcpp/include/avr-libcpp/suppress_sfr_macros/atmega328p.h b/libraries/avr-libcpp/include/avr-libcpp/suppress_sfr_macros/atmega328p.h
index 73b3267..5d0ee98 100644
--- a/libraries/avr-libcpp/include/avr-libcpp/suppress_sfr_macros/atmega328p.h
+++ b/libraries/avr-libcpp/include/avr-libcpp/suppress_sfr_macros/atmega328p.h
@@ -26,7 +26,7 @@
 #include <avr/io.h>
 
 #ifdef __AVR_ATmega328P__
-#ifdef AVRLIBCPP_SUPPRESS_SFR_MACROS
+#if AVRLIBCPP_SUPPRESS_SFR_MACROS
 
 #ifdef ACBG
 #undef ACBG
diff --git a/libraries/avr-libcpp/include/avr-libcpp/suppress_sfr_macros/megaavr_0_series.h b/libraries/avr-libcpp/include/avr-libcpp/suppress_sfr_macros/megaavr_0_series.h
index 7a63ec6..b938659 100644
--- a/libraries/avr-libcpp/include/avr-libcpp/suppress_sfr_macros/megaavr_0_series.h
+++ b/libraries/avr-libcpp/include/avr-libcpp/suppress_sfr_macros/megaavr_0_series.h
@@ -29,7 +29,7 @@
     || defined( __AVR_ATmega1608__ ) || defined( __AVR_ATmega1609__ ) \
     || defined( __AVR_ATmega3208__ ) || defined( __AVR_ATmega3209__ ) \
     || defined( __AVR_ATmega4808__ ) || defined( __AVR_ATmega4809__ )
-#ifdef AVRLIBCPP_SUPPRESS_SFR_MACROS
+#if AVRLIBCPP_SUPPRESS_SFR_MACROS
 
 #ifdef AC0
 #undef AC0