diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9e1158c77..147f104f8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,7 +4,7 @@ project(POLARSSL C)
 string(REGEX MATCH "Clang" CMAKE_COMPILER_IS_CLANG "${CMAKE_C_COMPILER_ID}")
 
 if(CMAKE_COMPILER_IS_GNUCC)
-  set(CMAKE_C_FLAGS "-Wall -Wextra -W -Wdeclaration-after-statement -Wlogical-op -Wwrite-strings")
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -W -Wdeclaration-after-statement -Wwrite-strings -Wlogical-op")
   set(CMAKE_C_FLAGS_RELEASE "-O2")
   set(CMAKE_C_FLAGS_DEBUG "-g3 -O0")
   set(CMAKE_C_FLAGS_COVERAGE "-g3 -O0 --coverage")
@@ -14,7 +14,7 @@ if(CMAKE_COMPILER_IS_GNUCC)
 endif(CMAKE_COMPILER_IS_GNUCC)
 
 if(CMAKE_COMPILER_IS_CLANG)
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -W -Wdeclaration-after-statement -Wpointer-arith -Wwrite-strings -Wdocumentation -Wunreachable-code")
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -W -Wdeclaration-after-statement -Wwrite-strings -Wpointer-arith -Wdocumentation -Wunreachable-code")
   set(CMAKE_C_FLAGS_RELEASE "-O2")
   set(CMAKE_C_FLAGS_DEBUG "-g3 -O0")
   set(CMAKE_C_FLAGS_COVERAGE "-g3 -O0 --coverage")
diff --git a/ChangeLog b/ChangeLog
index 20436d771..f38c0cff9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -5,6 +5,10 @@ PolarSSL ChangeLog (Sorted per branch, date)
 Features
    * Add function pk_check_pair() to test if public and private keys match.
 
+Bugfix
+   * User set CFLAGS were ignore by Cmake with gcc (introduced in 1.3.9, found
+     by Julian Ospald).
+
 Changes
    * Use deterministic nonces for AEAD ciphers in TLS by default (possible to
      switch back to random with POLARSSL_SSL_AEAD_RANDOM_IV in config.h).