--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -578,14 +578,14 @@ set(CMAKE_C_STANDARD_REQUIRED ON)
 set(CMAKE_C_EXTENSIONS ON)
 
 if (UNIX)
-  set( CMAKE_C_FLAGS "-Werror -Wdeclaration-after-statement -Wno-pointer-sign -Wall -Wmissing-prototypes -Wmissing-declarations -Wno-unused ${CMAKE_C_FLAGS}")
+  set( CMAKE_C_FLAGS "-Wdeclaration-after-statement -Wno-pointer-sign -Wall -Wmissing-prototypes -Wmissing-declarations -Wno-unused ${CMAKE_C_FLAGS}")
   set( CMAKE_C_FLAGS "-Wno-error=deprecated-declarations -Wno-error=parentheses ${CMAKE_C_FLAGS}")
-  set( CMAKE_CXX_FLAGS "-Werror -Wall -Wmissing-declarations -Wno-unused -Wno-error=parentheses ${CMAKE_CXX_FLAGS}")
+  set( CMAKE_CXX_FLAGS "-Wall -Wmissing-declarations -Wno-unused -Wno-error=parentheses ${CMAKE_CXX_FLAGS}")
   set( CMAKE_CXX_FLAGS "-Wno-error=deprecated-declarations ${REGISTER_CXXFLAG} ${CMAKE_CXX_FLAGS}")
   set( CMAKE_C_FLAGS_RELEASE "-O3 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 ${CMAKE_C_FLAGS}")
 endif()
 if (MINGW)
-  set( CMAKE_C_FLAGS "-Werror -Wdeclaration-after-statement -Wno-pointer-sign -Wall -Wunused -Wmissing-prototypes -Wmissing-declarations  -Wno-unused -Wno-error=deprecated-declarations ${CMAKE_C_FLAGS}")
+  set( CMAKE_C_FLAGS "-Wdeclaration-after-statement -Wno-pointer-sign -Wall -Wunused -Wmissing-prototypes -Wmissing-declarations  -Wno-unused -Wno-error=deprecated-declarations ${CMAKE_C_FLAGS}")
   set( CMAKE_CXX_FLAGS "-DWINVER=0x0500 -D_EMULATE_GLIBC=0 ${CMAKE_CXX_FLAGS}") # Workaround for bug in gtest on mingw, see https://github.com/google/googletest/issues/893 and https://github.com/google/googletest/issues/920
 endif()