diff --git a/src/egl_context.c b/src/egl_context.c
index b2d11a47..5e220de3 100644
--- a/src/egl_context.c
+++ b/src/egl_context.c
@@ -446,7 +446,7 @@ void _glfwTerminateEGL(void)
 
 #define setAttrib(a, v) \
 { \
-    assert((size_t) (index + 1) < sizeof(attribs) / sizeof(attribs[0])); \
+    assert(((size_t) index + 1) < sizeof(attribs) / sizeof(attribs[0])); \
     attribs[index++] = a; \
     attribs[index++] = v; \
 }
diff --git a/src/glx_context.c b/src/glx_context.c
index adace82d..1b32f9b5 100644
--- a/src/glx_context.c
+++ b/src/glx_context.c
@@ -435,7 +435,7 @@ void _glfwTerminateGLX(void)
 
 #define setAttrib(a, v) \
 { \
-    assert((size_t) (index + 1) < sizeof(attribs) / sizeof(attribs[0])); \
+    assert(((size_t) index + 1) < sizeof(attribs) / sizeof(attribs[0])); \
     attribs[index++] = a; \
     attribs[index++] = v; \
 }
diff --git a/src/input.c b/src/input.c
index 030cbe80..f74cd3fa 100644
--- a/src/input.c
+++ b/src/input.c
@@ -430,7 +430,7 @@ _GLFWjoystick* _glfwAllocJoystick(const char* name,
     js->present     = GLFW_TRUE;
     js->name        = _glfw_strdup(name);
     js->axes        = calloc(axisCount, sizeof(float));
-    js->buttons     = calloc(buttonCount + hatCount * 4, 1);
+    js->buttons     = calloc(buttonCount + (size_t) hatCount * 4, 1);
     js->hats        = calloc(hatCount, 1);
     js->axisCount   = axisCount;
     js->buttonCount = buttonCount;
diff --git a/src/monitor.c b/src/monitor.c
index ad12e56f..40f984bf 100644
--- a/src/monitor.c
+++ b/src/monitor.c
@@ -100,7 +100,7 @@ void _glfwInputMonitor(_GLFWmonitor* monitor, int action, int placement)
         {
             memmove(_glfw.monitors + 1,
                     _glfw.monitors,
-                    (_glfw.monitorCount - 1) * sizeof(_GLFWmonitor*));
+                    ((size_t) _glfw.monitorCount - 1) * sizeof(_GLFWmonitor*));
             _glfw.monitors[0] = monitor;
         }
         else
@@ -130,7 +130,7 @@ void _glfwInputMonitor(_GLFWmonitor* monitor, int action, int placement)
                 _glfw.monitorCount--;
                 memmove(_glfw.monitors + i,
                         _glfw.monitors + i + 1,
-                        (_glfw.monitorCount - i) * sizeof(_GLFWmonitor*));
+                        ((size_t) _glfw.monitorCount - i) * sizeof(_GLFWmonitor*));
                 break;
             }
         }
diff --git a/src/osmesa_context.c b/src/osmesa_context.c
index 03651ebf..907ad4e0 100644
--- a/src/osmesa_context.c
+++ b/src/osmesa_context.c
@@ -47,7 +47,7 @@ static void makeContextCurrentOSMesa(_GLFWwindow* window)
             free(window->context.osmesa.buffer);
 
             // Allocate the new buffer (width * height * 8-bit RGBA)
-            window->context.osmesa.buffer = calloc(4, width * height);
+            window->context.osmesa.buffer = calloc(4, (size_t) width * height);
             window->context.osmesa.width  = width;
             window->context.osmesa.height = height;
         }
@@ -188,7 +188,7 @@ void _glfwTerminateOSMesa(void)
 
 #define setAttrib(a, v) \
 { \
-    assert((size_t) (index + 1) < sizeof(attribs) / sizeof(attribs[0])); \
+    assert(((size_t) index + 1) < sizeof(attribs) / sizeof(attribs[0])); \
     attribs[index++] = a; \
     attribs[index++] = v; \
 }
diff --git a/src/wgl_context.c b/src/wgl_context.c
index 969895b1..754f4b44 100644
--- a/src/wgl_context.c
+++ b/src/wgl_context.c
@@ -533,7 +533,7 @@ void _glfwTerminateWGL(void)
 
 #define setAttrib(a, v) \
 { \
-    assert((size_t) (index + 1) < sizeof(attribs) / sizeof(attribs[0])); \
+    assert(((size_t) index + 1) < sizeof(attribs) / sizeof(attribs[0])); \
     attribs[index++] = a; \
     attribs[index++] = v; \
 }
diff --git a/src/win32_joystick.c b/src/win32_joystick.c
index 280ab477..d24eed35 100644
--- a/src/win32_joystick.c
+++ b/src/win32_joystick.c
@@ -414,7 +414,7 @@ static BOOL CALLBACK deviceCallback(const DIDEVICEINSTANCE* di, void* user)
 
     memset(&data, 0, sizeof(data));
     data.device = device;
-    data.objects = calloc(dc.dwAxes + dc.dwButtons + dc.dwPOVs,
+    data.objects = calloc(dc.dwAxes + (size_t) dc.dwButtons + dc.dwPOVs,
                           sizeof(_GLFWjoyobjectWin32));
 
     if (FAILED(IDirectInputDevice8_EnumObjects(device,
diff --git a/src/win32_window.c b/src/win32_window.c
index 728b6e07..7aca31a7 100644
--- a/src/win32_window.c
+++ b/src/win32_window.c
@@ -869,9 +869,9 @@ static LRESULT CALLBACK windowProc(HWND hWnd, UINT uMsg,
 
         case WM_INPUT:
         {
-            UINT size;
+            UINT size = 0;
             HRAWINPUT ri = (HRAWINPUT) lParam;
-            RAWINPUT* data;
+            RAWINPUT* data = NULL;
             int dx, dy;
 
             if (_glfw.win32.disabledCursorWindow != window)
@@ -1175,7 +1175,7 @@ static LRESULT CALLBACK windowProc(HWND hWnd, UINT uMsg,
             for (i = 0;  i < count;  i++)
             {
                 const UINT length = DragQueryFileW(drop, i, NULL, 0);
-                WCHAR* buffer = calloc(length + 1, sizeof(WCHAR));
+                WCHAR* buffer = calloc((size_t) length + 1, sizeof(WCHAR));
 
                 DragQueryFileW(drop, i, buffer, length + 1);
                 paths[i] = _glfwCreateUTF8FromWideStringWin32(buffer);