diff --git a/include/clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h b/include/clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h
index 23a1635..fba5692 100644
--- a/include/clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h
+++ b/include/clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h
@@ -129,6 +129,7 @@
     : K(StmtK), S(s), D(0), SM(&sm),
       Loc(genLocation(SourceLocation(), lac)),
       Range(genRange(lac)) {
+    assert(S);
     assert(Loc.isValid());
     assert(Range.isValid());
   }
@@ -137,6 +138,7 @@
   PathDiagnosticLocation(const Decl *d, const SourceManager &sm)
     : K(DeclK), S(0), D(d), SM(&sm),
       Loc(genLocation()), Range(genRange()) {
+    assert(D);
     assert(Loc.isValid());
     assert(Range.isValid());
   }
diff --git a/lib/StaticAnalyzer/Core/PathDiagnostic.cpp b/lib/StaticAnalyzer/Core/PathDiagnostic.cpp
index 50ebe3b..e398bae 100644
--- a/lib/StaticAnalyzer/Core/PathDiagnostic.cpp
+++ b/lib/StaticAnalyzer/Core/PathDiagnostic.cpp
@@ -237,9 +237,15 @@
     case RangeK:
       break;
     case StmtK:
+      // Defensive checking.
+      if (!S)
+        break;
       return FullSourceLoc(getValidSourceLocation(S, LAC),
                            const_cast<SourceManager&>(*SM));
     case DeclK:
+      // Defensive checking.
+      if (!D)
+        break;
       return FullSourceLoc(D->getLocation(), const_cast<SourceManager&>(*SM));
   }