diff --git a/src/context.c b/src/context.c
index cda16d2d..7bedd1ea 100644
--- a/src/context.c
+++ b/src/context.c
@@ -506,7 +506,7 @@ GLFWbool _glfwIsValidContext(const _GLFWctxconfig* ctxconfig)
     return GLFW_TRUE;
 }
 
-int _glfwStringInExtensionString(const char* string, const char* extensions)
+GLFWbool _glfwStringInExtensionString(const char* string, const char* extensions)
 {
     const char* start = extensions;
 
diff --git a/src/input.c b/src/input.c
index b1aaaa9e..94f491cf 100644
--- a/src/input.c
+++ b/src/input.c
@@ -156,7 +156,7 @@ void _glfwInputKey(_GLFWwindow* window, int key, int scancode, int action, int m
         window->callbacks.key((GLFWwindow*) window, key, scancode, action, mods);
 }
 
-void _glfwInputChar(_GLFWwindow* window, unsigned int codepoint, int mods, int plain)
+void _glfwInputChar(_GLFWwindow* window, unsigned int codepoint, int mods, GLFWbool plain)
 {
     if (codepoint < 32 || (codepoint > 126 && codepoint < 160))
         return;
@@ -210,7 +210,7 @@ void _glfwInputCursorMotion(_GLFWwindow* window, double x, double y)
         window->callbacks.cursorPos((GLFWwindow*) window, x, y);
 }
 
-void _glfwInputCursorEnter(_GLFWwindow* window, int entered)
+void _glfwInputCursorEnter(_GLFWwindow* window, GLFWbool entered)
 {
     if (window->callbacks.cursorEnter)
         window->callbacks.cursorEnter((GLFWwindow*) window, entered);
diff --git a/src/internal.h b/src/internal.h
index a2fadba0..2410b075 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -708,7 +708,7 @@ void _glfwInputFramebufferSize(_GLFWwindow* window, int width, int height);
  *  `GLFW_FALSE` if it was restored.
  *  @ingroup event
  */
-void _glfwInputWindowIconify(_GLFWwindow* window, int iconified);
+void _glfwInputWindowIconify(_GLFWwindow* window, GLFWbool iconified);
 
 /*! @brief Notifies shared code of a window damage event.
  *  @param[in] window The window that received the event.
@@ -739,7 +739,7 @@ void _glfwInputKey(_GLFWwindow* window, int key, int scancode, int action, int m
  *  `GLFW_FALSE` otherwise.
  *  @ingroup event
  */
-void _glfwInputChar(_GLFWwindow* window, unsigned int codepoint, int mods, int plain);
+void _glfwInputChar(_GLFWwindow* window, unsigned int codepoint, int mods, GLFWbool plain);
 
 /*! @brief Notifies shared code of a scroll event.
  *  @param[in] window The window that received the event.
@@ -773,7 +773,7 @@ void _glfwInputCursorMotion(_GLFWwindow* window, double x, double y);
  *  window, or `GLFW_FALSE` if it left it.
  *  @ingroup event
  */
-void _glfwInputCursorEnter(_GLFWwindow* window, int entered);
+void _glfwInputCursorEnter(_GLFWwindow* window, GLFWbool entered);
 
 /*! @ingroup event
  */
@@ -825,7 +825,7 @@ void _glfwSplitBPP(int bpp, int* red, int* green, int* blue);
  *  @return `GLFW_TRUE` if the extension was found, or `GLFW_FALSE` otherwise.
  *  @ingroup utility
  */
-int _glfwStringInExtensionString(const char* string, const char* extensions);
+GLFWbool _glfwStringInExtensionString(const char* string, const char* extensions);
 
 /*! @brief Chooses the framebuffer config that best matches the desired one.
  *  @param[in] desired The desired framebuffer config.
diff --git a/src/window.c b/src/window.c
index 6eac705c..e9e01e50 100644
--- a/src/window.c
+++ b/src/window.c
@@ -82,7 +82,7 @@ void _glfwInputWindowSize(_GLFWwindow* window, int width, int height)
         window->callbacks.size((GLFWwindow*) window, width, height);
 }
 
-void _glfwInputWindowIconify(_GLFWwindow* window, int iconified)
+void _glfwInputWindowIconify(_GLFWwindow* window, GLFWbool iconified)
 {
     if (window->callbacks.iconify)
         window->callbacks.iconify((GLFWwindow*) window, iconified);