diff --git a/src/posix_tls.c b/src/posix_tls.c
index f264f0ba..849a1e0b 100644
--- a/src/posix_tls.c
+++ b/src/posix_tls.c
@@ -32,7 +32,7 @@
 //////                       GLFW internal API                      //////
 //////////////////////////////////////////////////////////////////////////
 
-int _glfwCreateContextTLS(void)
+GLFWbool _glfwCreateContextTLS(void)
 {
     if (pthread_key_create(&_glfw.posix_tls.context, NULL) != 0)
     {
diff --git a/src/posix_tls.h b/src/posix_tls.h
index 124f2145..3304a56a 100644
--- a/src/posix_tls.h
+++ b/src/posix_tls.h
@@ -43,7 +43,7 @@ typedef struct _GLFWtlsPOSIX
 } _GLFWtlsPOSIX;
 
 
-int _glfwCreateContextTLS(void);
+GLFWbool _glfwCreateContextTLS(void);
 void _glfwDestroyContextTLS(void);
 void _glfwSetContextTLS(_GLFWwindow* context);
 
diff --git a/src/win32_tls.c b/src/win32_tls.c
index 058d5d2b..75e71097 100644
--- a/src/win32_tls.c
+++ b/src/win32_tls.c
@@ -32,7 +32,7 @@
 //////                       GLFW internal API                      //////
 //////////////////////////////////////////////////////////////////////////
 
-int _glfwCreateContextTLS(void)
+GLFWbool _glfwCreateContextTLS(void)
 {
     _glfw.win32_tls.context = TlsAlloc();
     if (_glfw.win32_tls.context == TLS_OUT_OF_INDEXES)
diff --git a/src/win32_tls.h b/src/win32_tls.h
index 8848964a..0d037dc1 100644
--- a/src/win32_tls.h
+++ b/src/win32_tls.h
@@ -41,7 +41,7 @@ typedef struct _GLFWtlsWin32
 } _GLFWtlsWin32;
 
 
-int _glfwCreateContextTLS(void);
+GLFWbool _glfwCreateContextTLS(void);
 void _glfwDestroyContextTLS(void);
 void _glfwSetContextTLS(_GLFWwindow* context);