--- cg3-1.3.2/CMakeLists.txt.orig	2021-03-23 19:52:01.468693496 +0100
+++ cg3-1.3.2/CMakeLists.txt	2021-03-23 20:06:00.977478820 +0100
@@ -50,7 +50,11 @@
 	include(CheckCCompilerFlag)
 	include(CheckCXXCompilerFlag)
 
-	foreach(flag "-Wno-unused-result" "-flto")
+	set(flags_to_check "-Wno-unused-result")
+	if(BUILD_SHARED_LIBS)
+		set(flags_to_check "${flags_to_check} -flto")
+	endif()
+	foreach(flag ${flags_to_check})
 		string(REGEX REPLACE "[^A-Za-z0-9]" "" _flag ${flag})
 		CHECK_CXX_COMPILER_FLAG(${flag} COMPILER_SUPPORTS_${_flag})
 		if(COMPILER_SUPPORTS_${_flag})