diff --git a/CMakeLists.txt b/CMakeLists.txt
index 70c1d86..3bf7cf8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -15,7 +15,7 @@ set(PROJECT_VERSION "${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}.${PROJECT
 option(ENABLE_CUSTOM_COMPILER_FLAGS "Enables custom compiler flags for Clang and GCC" ON)
 if (ENABLE_CUSTOM_COMPILER_FLAGS)
     if(("${CMAKE_C_COMPILER_ID}" MATCHES "GNU") OR ("${CMAKE_C_COMPILER_ID}" MATCHES "Clang"))
-        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c89 -pedantic -Wall -Wextra -Werror -Wstrict-prototypes -Wwrite-strings -Wshadow -Winit-self -Wcast-align -Wformat=2")
+        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c89 -pedantic -Wall -Wextra -Werror -Wstrict-prototypes -Wwrite-strings -Wshadow -Winit-self -Wcast-align -Wformat=2 -Wmissing-prototypes")
     endif()
 endif()
 
diff --git a/Makefile b/Makefile
index e4b8be9..9b1c63e 100644
--- a/Makefile
+++ b/Makefile
@@ -20,14 +20,14 @@ INSTALL_LIBRARY_PATH = $(DESTDIR)$(PREFIX)/$(LIBRARY_PATH)
 
 INSTALL ?= cp -a
 
-R_CFLAGS = -fPIC -std=c89 -pedantic -Wall -Werror -Wstrict-prototypes -Wwrite-strings -Wshadow -Winit-self -Wcast-align -Wformat=2 $(CFLAGS)
+R_CFLAGS = -fPIC -std=c89 -pedantic -Wall -Werror -Wstrict-prototypes -Wwrite-strings -Wshadow -Winit-self -Wcast-align -Wformat=2 -Wmissing-prototypes $(CFLAGS)
 
 uname := $(shell sh -c 'uname -s 2>/dev/null || echo false')
 
 #library file extensions
 SHARED = so
 STATIC = a
-
+ 
 ## create dynamic (shared) library on Darwin (base OS for MacOSX and IOS)
 ifeq (Darwin, $(uname))
 	SHARED = dylib