diff --git a/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
@@ -1433,6 +1433,14 @@
                 RetType{Ssize_tTy}),
       GetLineSummary);
 
+  // char *getenv(const char *name);
+  addToFunctionSummaryMap(
+      "getenv", Signature(ArgTypes{ConstCharPtrTy}, RetType{CharPtrTy}),
+      Summary(NoEvalCall)
+          .Case({NotNull(Ret)})
+          .Case({NotNull(Ret)->negate()})
+          .ArgConstraint(NotNull(ArgNo(0))));
+
   if (ModelPOSIX) {
 
     // long a64l(const char *str64);
diff --git a/clang/test/Analysis/std-c-library-functions.c b/clang/test/Analysis/std-c-library-functions.c
--- a/clang/test/Analysis/std-c-library-functions.c
+++ b/clang/test/Analysis/std-c-library-functions.c
@@ -254,3 +254,11 @@
   f = ispunct;
   clang_analyzer_eval(f('A')); // expected-warning{{FALSE}}
 }
+
+char *getenv(const char *name);
+void test_getenv() {
+  // getenv() bifurcates here.
+  clang_analyzer_eval(getenv("FOO") == 0);
+  // expected-warning@-1 {{TRUE}}
+  // expected-warning@-2 {{FALSE}}
+}