diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1f556f3..607b2c4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -21,7 +21,14 @@
 string(REGEX MATCH "Clang" CMAKE_COMPILER_IS_CLANG "${CMAKE_C_COMPILER_ID}")
 
 if(CMAKE_COMPILER_IS_GNUCC)
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -W -Wdeclaration-after-statement -Wwrite-strings -Wlogical-op")
+    # some warnings we want are not available with old GCC versions
+    # note: starting with CMake 2.8 we could use CMAKE_C_COMPILER_VERSION
+    execute_process(COMMAND ${CMAKE_C_COMPILER} -dumpversion
+                    OUTPUT_VARIABLE GCC_VERSION)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -W -Wdeclaration-after-statement -Wwrite-strings")
+    if (GCC_VERSION VERSION_GREATER 4.5 OR GCC_VERSION VERSION_EQUAL 4.5)
+        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wlogical-op")
+    endif()
     set(CMAKE_C_FLAGS_RELEASE     "-O2")
     set(CMAKE_C_FLAGS_DEBUG       "-O0 -g3")
     set(CMAKE_C_FLAGS_COVERAGE    "-O0 -g3 --coverage")