--- a/gfx/gl/GLReadTexImageHelper.cpp
+++ b/gfx/gl/GLReadTexImageHelper.cpp
@@ -388,32 +388,28 @@ ReadPixelsIntoDataSurface(GLContext* gl,
             return;
         }
 
         readSurf = tempSurf;
     }
     MOZ_ASSERT(readAlignment);
     MOZ_ASSERT(reinterpret_cast<uintptr_t>(readSurf->GetData()) % readAlignment == 0);
 
-    GLint currentPackAlignment = 0;
-    gl->fGetIntegerv(LOCAL_GL_PACK_ALIGNMENT, &currentPackAlignment);
-
-    if (currentPackAlignment != readAlignment)
-        gl->fPixelStorei(LOCAL_GL_PACK_ALIGNMENT, readAlignment);
-
     GLsizei width = dest->GetSize().width;
     GLsizei height = dest->GetSize().height;
 
-    gl->fReadPixels(0, 0,
-                    width, height,
-                    readFormat, readType,
-                    readSurf->GetData());
+    {
+        ScopedPackState safePackState(gl);
+        gl->fPixelStorei(LOCAL_GL_PACK_ALIGNMENT, readAlignment);
 
-    if (currentPackAlignment != readAlignment)
-        gl->fPixelStorei(LOCAL_GL_PACK_ALIGNMENT, currentPackAlignment);
+        gl->fReadPixels(0, 0,
+                        width, height,
+                        readFormat, readType,
+                        readSurf->GetData());
+    }
 
     if (readSurf != dest) {
         MOZ_ASSERT(readFormat == LOCAL_GL_RGBA);
         MOZ_ASSERT(readType == LOCAL_GL_UNSIGNED_BYTE);
         gfx::Factory::CopyDataSourceSurface(readSurf, dest);
     }
 
     // Check if GL is giving back 1.0 alpha for