diff --git a/core/fpdfapi/page/cpdf_colorspace.cpp b/core/fpdfapi/page/cpdf_colorspace.cpp
index 0b550f5..9d94acd 100644
--- a/core/fpdfapi/page/cpdf_colorspace.cpp
+++ b/core/fpdfapi/page/cpdf_colorspace.cpp
@@ -550,8 +550,7 @@
     case Family::kDeviceCMYK:
       return 4;
     default:
-      NOTREACHED();
-      return 4;
+      NOTREACHED_NORETURN();
   }
 }
 
@@ -1070,8 +1069,7 @@
     return GetStockCS(Family::kDeviceRGB);
   if (nComponents == 4)
     return GetStockCS(Family::kDeviceCMYK);
-  NOTREACHED();
-  return nullptr;
+  NOTREACHED_NORETURN();
 }
 
 // static
diff --git a/core/fpdfapi/page/cpdf_devicecs.cpp b/core/fpdfapi/page/cpdf_devicecs.cpp
index 0fad1b1..5590c5b 100644
--- a/core/fpdfapi/page/cpdf_devicecs.cpp
+++ b/core/fpdfapi/page/cpdf_devicecs.cpp
@@ -40,8 +40,7 @@
                                std::set<const CPDF_Object*>* pVisited) {
   // Unlike other classes that inherit from CPDF_ColorSpace, CPDF_DeviceCS is
   // never loaded by CPDF_ColorSpace.
-  NOTREACHED();
-  return 0;
+  NOTREACHED_NORETURN();
 }
 
 bool CPDF_DeviceCS::GetRGB(pdfium::span<const float> pBuf,
@@ -72,8 +71,7 @@
       }
       return true;
     default:
-      NOTREACHED();
-      return false;
+      NOTREACHED_NORETURN();
   }
 }
 
@@ -141,7 +139,6 @@
       }
       break;
     default:
-      NOTREACHED();
-      break;
+      NOTREACHED_NORETURN();
   }
 }
diff --git a/core/fpdfapi/page/cpdf_patterncs.cpp b/core/fpdfapi/page/cpdf_patterncs.cpp
index cae8f49..7abc0b2 100644
--- a/core/fpdfapi/page/cpdf_patterncs.cpp
+++ b/core/fpdfapi/page/cpdf_patterncs.cpp
@@ -45,8 +45,7 @@
                             float* R,
                             float* G,
                             float* B) const {
-  NOTREACHED();
-  return false;
+  NOTREACHED_NORETURN();
 }
 
 const CPDF_PatternCS* CPDF_PatternCS::AsPatternCS() const {
diff --git a/core/fpdfapi/page/cpdf_psengine.cpp b/core/fpdfapi/page/cpdf_psengine.cpp
index 95f3ea3..da7b00d 100644
--- a/core/fpdfapi/page/cpdf_psengine.cpp
+++ b/core/fpdfapi/page/cpdf_psengine.cpp
@@ -110,8 +110,7 @@
   if (m_op == PSOP_CONST)
     return m_value;
 
-  NOTREACHED();
-  return 0;
+  NOTREACHED_NORETURN();
 }
 
 bool CPDF_PSEngine::Execute() {
diff --git a/core/fpdfapi/page/cpdf_shadingpattern.cpp b/core/fpdfapi/page/cpdf_shadingpattern.cpp
index 00f5a03..9d26ba9 100644
--- a/core/fpdfapi/page/cpdf_shadingpattern.cpp
+++ b/core/fpdfapi/page/cpdf_shadingpattern.cpp
@@ -120,8 +120,7 @@
       break;
     }
     default: {
-      NOTREACHED();
-      return false;
+      NOTREACHED_NORETURN();
     }
   }
 
@@ -148,10 +147,8 @@
              ValidateFunctions(nNumColorSpaceComponents, 1, 1);
     }
     default:
-      break;
+      NOTREACHED_NORETURN();
   }
-  NOTREACHED();
-  return false;
 }
 
 bool CPDF_ShadingPattern::ValidateFunctions(
diff --git a/core/fpdfapi/page/cpdf_streamcontentparser.cpp b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
index c7c2911..4226754 100644
--- a/core/fpdfapi/page/cpdf_streamcontentparser.cpp
+++ b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
@@ -354,8 +354,7 @@
   if (param.m_Type == ContentParam::Type::kObject)
     return param.m_pObject;
 
-  NOTREACHED();
-  return nullptr;
+  NOTREACHED_NORETURN();
 }
 
 ByteString CPDF_StreamContentParser::GetString(uint32_t index) const {