diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -9790,6 +9790,10 @@
   const VectorType *RHSVecType = RHSType->getAs<VectorType>();
   assert(LHSVecType || RHSVecType);
 
+  if ((LHSVecType && LHSVecType->getElementType()->isBFloat16Type()) ||
+      (RHSVecType && RHSVecType->getElementType()->isBFloat16Type()))
+    return InvalidOperands(Loc, LHS, RHS);
+
   // AltiVec-style "vector bool op vector bool" combinations are allowed
   // for some operators but not others.
   if (!AllowBothBool &&
diff --git a/clang/test/Sema/arm-bfloat.cpp b/clang/test/Sema/arm-bfloat.cpp
--- a/clang/test/Sema/arm-bfloat.cpp
+++ b/clang/test/Sema/arm-bfloat.cpp
@@ -27,3 +27,21 @@
   fp16 = bf16; // expected-error {{assigning to '__fp16' from incompatible type '__bf16'}}
   bf16 + (b ? fp16 : bf16); // expected-error {{incompatible operand types ('__fp16' and '__bf16')}}
 }
+
+#include <arm_neon.h>
+
+void test_vector(bfloat16x4_t a, bfloat16x4_t b, float16x4_t c) {
+  a + b; // expected-error {{invalid operands to binary expression ('bfloat16x4_t' (vector of 4 'bfloat16_t' values) and 'bfloat16x4_t')}}
+  a - b; // expected-error {{invalid operands to binary expression ('bfloat16x4_t' (vector of 4 'bfloat16_t' values) and 'bfloat16x4_t')}}
+  a * b; // expected-error {{invalid operands to binary expression ('bfloat16x4_t' (vector of 4 'bfloat16_t' values) and 'bfloat16x4_t')}}
+  a / b; // expected-error {{invalid operands to binary expression ('bfloat16x4_t' (vector of 4 'bfloat16_t' values) and 'bfloat16x4_t')}}
+
+  a + c; // expected-error {{invalid operands to binary expression ('bfloat16x4_t' (vector of 4 'bfloat16_t' values) and 'float16x4_t' (vector of 4 'float16_t' values))}}
+  a - c; // expected-error {{invalid operands to binary expression ('bfloat16x4_t' (vector of 4 'bfloat16_t' values) and 'float16x4_t' (vector of 4 'float16_t' values))}}
+  a * c; // expected-error {{invalid operands to binary expression ('bfloat16x4_t' (vector of 4 'bfloat16_t' values) and 'float16x4_t' (vector of 4 'float16_t' values))}}
+  a / c; // expected-error {{invalid operands to binary expression ('bfloat16x4_t' (vector of 4 'bfloat16_t' values) and 'float16x4_t' (vector of 4 'float16_t' values))}}
+  c + b; // expected-error {{invalid operands to binary expression ('float16x4_t' (vector of 4 'float16_t' values) and 'bfloat16x4_t' (vector of 4 'bfloat16_t' values))}}
+  c - b; // expected-error {{invalid operands to binary expression ('float16x4_t' (vector of 4 'float16_t' values) and 'bfloat16x4_t' (vector of 4 'bfloat16_t' values))}}
+  c * b; // expected-error {{invalid operands to binary expression ('float16x4_t' (vector of 4 'float16_t' values) and 'bfloat16x4_t' (vector of 4 'bfloat16_t' values))}}
+  c / b; // expected-error {{invalid operands to binary expression ('float16x4_t' (vector of 4 'float16_t' values) and 'bfloat16x4_t' (vector of 4 'bfloat16_t' values))}}
+}