diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2c10e4a..7f9eb7e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -92,24 +92,6 @@ if(MSVC OR CMAKE_C_COMPILER_ID MATCHES "Clang")
 endif()
 
 add_definitions(-DUSE_ARRAY)
-if(CMAKE_C_COMPILER_ID STREQUAL "GNU" OR CMAKE_C_COMPILER_ID MATCHES "Clang")
-  message(STATUS "adding GCC/Clang options ")
-  add_definitions(-std=gnu99 -Wall -Wextra -pedantic)
-  if(COSE_C_FATAL_WARNINGS)
-    add_definitions(-Werror)
-  endif()
-  if(COSE_C_OPTIMIZE)
-    add_definitions(-Os)
-  endif()
-  add_definitions(-DNDEBUG)
-elseif(MSVC)
-  add_definitions(/W4)
-  if(COSE_C_FATAL_WARNINGS)
-    add_definitions(/WX)
-  endif()
-else()
-  message(FATAL_ERROR "unhandled compiler id: ${CMAKE_C_COMPILER_ID}")
-endif()
 
 if(versbose)
   set(CMAKE_VERBOSE_MAKEFILE ON)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index fb4464e..c41e555 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,3 +1,22 @@
+if(CMAKE_C_COMPILER_ID STREQUAL "GNU" OR CMAKE_C_COMPILER_ID MATCHES "Clang")
+  message(STATUS "adding GCC/Clang options ")
+  add_definitions(-std=gnu99 -Wall -Wextra -pedantic)
+  if(COSE_C_FATAL_WARNINGS)
+    add_definitions(-Werror)
+  endif()
+  if(COSE_C_OPTIMIZE)
+    add_definitions(-Os)
+  endif()
+  add_definitions(-DNDEBUG)
+elseif(MSVC)
+  add_definitions(/W4)
+  if(COSE_C_FATAL_WARNINGS)
+    add_definitions(/WX)
+  endif()
+else()
+  message(FATAL_ERROR "unhandled compiler id: ${CMAKE_C_COMPILER_ID}")
+endif()
+
 add_library(${PROJECT_NAME})
 
 if(COSE_C_USE_MBEDTLS)