diff --git a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
--- a/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/BuildLibCalls.cpp
@@ -429,7 +429,6 @@
     Changed |= setOnlyReadsMemory(F, 1);
     return Changed;
   case LibFunc_feof:
-  case LibFunc_free:
   case LibFunc_fseek:
   case LibFunc_ftell:
   case LibFunc_fgetc:
@@ -446,6 +445,10 @@
     Changed |= setDoesNotThrow(F);
     Changed |= setDoesNotCapture(F, 0);
     return Changed;
+  case LibFunc_free:
+    // Free is nothrow but does capture the argument.
+    Changed |= setDoesNotThrow(F);
+    return Changed;
   case LibFunc_ferror:
     Changed |= setDoesNotThrow(F);
     Changed |= setDoesNotCapture(F, 0);
diff --git a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
--- a/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
+++ b/llvm/test/Transforms/InferFunctionAttrs/annotate.ll
@@ -451,7 +451,8 @@
 ; CHECK: declare i64 @fread(i8* nocapture, i64, i64, %opaque* nocapture) [[G1]]
 declare i64 @fread(i8*, i64, i64, %opaque*)
 
-; CHECK: declare void @free(i8* nocapture) [[G3:#[0-9]+]]
+; Make sure there is *no* nocapture here.
+; CHECK: declare void @free(i8*) [[G3:#[0-9]+]]
 declare void @free(i8*)
 
 ; CHECK: declare double @frexp(double, i32* nocapture) [[G1]]