diff --git a/core/fpdfapi/page/cpdf_dib.cpp b/core/fpdfapi/page/cpdf_dib.cpp
index ae36c08..e58ed3c 100644
--- a/core/fpdfapi/page/cpdf_dib.cpp
+++ b/core/fpdfapi/page/cpdf_dib.cpp
@@ -1175,6 +1175,7 @@
   if (m_pColorSpace) {
     TranslateScanline24bpp(m_LineBuf.data(), pSrcLine);
     pSrcLine = m_LineBuf.data();
+    src_pitch_value = 3 * m_Width;
   }
   if (!m_bColorKey)
     return {pSrcLine, src_pitch_value};