diff --git a/src/cocoa_window.m b/src/cocoa_window.m
index 7cdb826b..f32d078e 100644
--- a/src/cocoa_window.m
+++ b/src/cocoa_window.m
@@ -668,7 +668,7 @@ static int translateKey(unsigned int key)
 //
 static NSString* findAppName(void)
 {
-    unsigned int i;
+    size_t i;
     NSDictionary* infoDictionary = [[NSBundle mainBundle] infoDictionary];
 
     // Keys to search for as potential application names
diff --git a/src/egl_context.c b/src/egl_context.c
index f136b332..8fa9a949 100644
--- a/src/egl_context.c
+++ b/src/egl_context.c
@@ -246,7 +246,7 @@ void _glfwTerminateContextAPI(void)
 { \
     attribs[index++] = attribName; \
     attribs[index++] = attribValue; \
-    assert(index < sizeof(attribs) / sizeof(attribs[0])); \
+    assert((size_t) index < sizeof(attribs) / sizeof(attribs[0])); \
 }
 
 // Prepare for creation of the OpenGL context
diff --git a/src/glx_context.c b/src/glx_context.c
index d22d5f57..0774e093 100644
--- a/src/glx_context.c
+++ b/src/glx_context.c
@@ -344,7 +344,7 @@ void _glfwTerminateContextAPI(void)
 { \
     attribs[index++] = attribName; \
     attribs[index++] = attribValue; \
-    assert(index < sizeof(attribs) / sizeof(attribs[0])); \
+    assert((size_t) index < sizeof(attribs) / sizeof(attribs[0])); \
 }
 
 // Prepare for creation of the OpenGL context
diff --git a/src/wgl_context.c b/src/wgl_context.c
index 7bac477c..14ee9c6d 100644
--- a/src/wgl_context.c
+++ b/src/wgl_context.c
@@ -332,7 +332,7 @@ void _glfwTerminateContextAPI(void)
 { \
     attribs[index++] = attribName; \
     attribs[index++] = attribValue; \
-    assert(index < sizeof(attribs) / sizeof(attribs[0])); \
+    assert((size_t) index < sizeof(attribs) / sizeof(attribs[0])); \
 }
 
 // Prepare for creation of the OpenGL context
diff --git a/src/x11_clipboard.c b/src/x11_clipboard.c
index e8e2ca92..afa24746 100644
--- a/src/x11_clipboard.c
+++ b/src/x11_clipboard.c
@@ -273,11 +273,11 @@ void _glfwPlatformSetClipboardString(_GLFWwindow* window, const char* string)
 
 const char* _glfwPlatformGetClipboardString(_GLFWwindow* window)
 {
-    int i;
+    size_t i;
     const Atom formats[] = { _glfw.x11.UTF8_STRING,
                              _glfw.x11.COMPOUND_STRING,
                              XA_STRING };
-    const int formatCount = sizeof(formats) / sizeof(formats[0]);
+    const size_t formatCount = sizeof(formats) / sizeof(formats[0]);
 
     if (_glfwFindWindowByHandle(XGetSelectionOwner(_glfw.x11.display,
                                                    _glfw.x11.CLIPBOARD)))
diff --git a/src/x11_joystick.c b/src/x11_joystick.c
index 37bd56f2..25de938d 100644
--- a/src/x11_joystick.c
+++ b/src/x11_joystick.c
@@ -162,7 +162,8 @@ static void pollJoystickEvents(void)
 void _glfwInitJoysticks(void)
 {
 #ifdef __linux__
-    int i, joy = 0;
+    int joy = 0;
+    size_t i;
     regex_t regex;
     DIR* dir;
     const char* dirs[] =