diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index 3ae79eeca47..cbb58bb033a 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -66,6 +66,11 @@ public:
     this->TD = TD;
     if (CI->getCalledFunction())
       Context = &CI->getCalledFunction()->getContext();
+
+    // We never change the calling convention.
+    if (CI->getCallingConv() != llvm::CallingConv::C)
+      return NULL;
+
     return CallOptimizer(CI->getCalledFunction(), CI, B);
   }
 };
diff --git a/test/Transforms/SimplifyLibCalls/PR7357.ll b/test/Transforms/SimplifyLibCalls/PR7357.ll
new file mode 100644
index 00000000000..6d5c1d5047d
--- /dev/null
+++ b/test/Transforms/SimplifyLibCalls/PR7357.ll
@@ -0,0 +1,16 @@
+; RUN: opt < %s -default-data-layout="e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-n32" -simplify-libcalls -S | FileCheck %s
+@.str1 = private constant [11 x i8] c"(){};[]&|:\00", align 4
+
+; check that simplify libcalls will not replace a call with one calling
+; convention with a new call with a different calling convention.
+
+; CHECK: define arm_aapcscc i32 @foo(i32 %argc)
+; CHECK: call arm_aapcscc  i8* @strchr
+define arm_aapcscc i32 @foo(i32 %argc) nounwind {
+bb.nph:
+  call arm_aapcscc  i8* @strchr(i8* getelementptr ([11 x i8]* @.str1, i32 0,
+i32 0), i32 %argc) nounwind readonly
+  ret i32 0
+}
+
+declare arm_aapcscc i8* @strchr(i8*, i32) nounwind readonly