diff --git a/extern/agg24-svn/include/agg_rasterizer_cells_aa.h b/extern/agg24-svn/include/agg_rasterizer_cells_aa.h
index 3809bdb70510..d1cc705405dc 100644
--- a/extern/agg24-svn/include/agg_rasterizer_cells_aa.h
+++ b/extern/agg24-svn/include/agg_rasterizer_cells_aa.h
@@ -329,6 +329,7 @@ namespace agg
             int cy = (y1 + y2) >> 1;
             line(x1, y1, cx, cy);
             line(cx, cy, x2, y2);
+            return;
         }
 
         int dy = y2 - y1;
diff --git a/src/_backend_agg.cpp b/src/_backend_agg.cpp
index de06d0bfb2ab..6ae11167e884 100644
--- a/src/_backend_agg.cpp
+++ b/src/_backend_agg.cpp
@@ -29,7 +29,7 @@ RendererAgg::RendererAgg(unsigned int width, unsigned int height, double dpi)
     : width(width),
       height(height),
       dpi(dpi),
-      NUMBYTES(width * height * 4),
+      NUMBYTES((size_t)width * (size_t)height * 4),
       pixBuffer(NULL),
       renderingBuffer(),
       alphaBuffer(NULL),
diff --git a/src/_backend_agg_wrapper.cpp b/src/_backend_agg_wrapper.cpp
index e08642e248ef..49a271b96b6a 100644
--- a/src/_backend_agg_wrapper.cpp
+++ b/src/_backend_agg_wrapper.cpp
@@ -95,7 +95,7 @@ int PyBufferRegion_get_buffer(PyBufferRegion *self, Py_buffer *buf, int flags)
     Py_INCREF(self);
     buf->obj = (PyObject *)self;
     buf->buf = self->x->get_data();
-    buf->len = self->x->get_width() * self->x->get_height() * 4;
+    buf->len = (Py_ssize_t)self->x->get_width() * (Py_ssize_t)self->x->get_height() * 4;
     buf->readonly = 0;
     buf->format = (char *)"B";
     buf->ndim = 3;
@@ -531,7 +531,7 @@ int PyRendererAgg_get_buffer(PyRendererAgg *self, Py_buffer *buf, int flags)
     Py_INCREF(self);
     buf->obj = (PyObject *)self;
     buf->buf = self->x->pixBuffer;
-    buf->len = self->x->get_width() * self->x->get_height() * 4;
+    buf->len = (Py_ssize_t)self->x->get_width() * (Py_ssize_t)self->x->get_height() * 4;
     buf->readonly = 0;
     buf->format = (char *)"B";
     buf->ndim = 3;