diff --git a/source/val/validate_cfg.cpp b/source/val/validate_cfg.cpp
index f3019d1..1c279f6 100644
--- a/source/val/validate_cfg.cpp
+++ b/source/val/validate_cfg.cpp
@@ -62,6 +62,15 @@
     }
   }
 
+  if (!_.options()->before_hlsl_legalization) {
+    if (type_opcode == SpvOpTypeSampledImage ||
+        (_.HasCapability(SpvCapabilityShader) &&
+         (type_opcode == SpvOpTypeImage || type_opcode == SpvOpTypeSampler))) {
+      return _.diag(SPV_ERROR_INVALID_ID, inst)
+             << "Result type cannot be Op" << spvOpcodeString(type_opcode);
+    }
+  }
+
   // Create a uniqued vector of predecessor ids for comparison against
   // incoming values. OpBranchConditional %cond %label %label produces two
   // predecessors in the CFG.
diff --git a/test/val/val_cfg_test.cpp b/test/val/val_cfg_test.cpp
index 4cf4029..0d09642 100644
--- a/test/val/val_cfg_test.cpp
+++ b/test/val/val_cfg_test.cpp
@@ -4296,6 +4296,213 @@
   EXPECT_EQ(SPV_SUCCESS, ValidateInstructions());
 }
 
+TEST_F(ValidateCFG, PhiResultInvalidSampler) {
+  const std::string text = R"(
+OpCapability Shader
+OpCapability Linkage
+OpMemoryModel Logical GLSL450
+%void = OpTypeVoid
+%bool = OpTypeBool
+%f32 = OpTypeFloat 32
+%sampler = OpTypeSampler
+%ptr_uc_sampler = OpTypePointer UniformConstant %sampler
+%sampler_var = OpVariable %ptr_uc_sampler UniformConstant
+%undef_bool = OpUndef %bool
+%undef_sampler = OpUndef %sampler
+%void_fn = OpTypeFunction %void
+%fn = OpFunction %void None %void_fn
+%entry = OpLabel
+%ld_sampler = OpLoad %sampler %sampler_var
+OpBranch %loop
+%loop = OpLabel
+%phi = OpPhi %sampler %undef_sampler %entry %ld_sampler %loop
+OpLoopMerge %exit %loop None
+OpBranchConditional %undef_bool %exit %loop
+%exit = OpLabel
+OpReturn
+OpFunctionEnd
+)";
+
+  CompileSuccessfully(text);
+  ASSERT_EQ(SPV_ERROR_INVALID_ID, ValidateInstructions());
+  EXPECT_THAT(getDiagnosticString(),
+              HasSubstr("Result type cannot be OpTypeSampler"));
+}
+
+TEST_F(ValidateCFG, PhiResultInvalidImage) {
+  const std::string text = R"(
+OpCapability Shader
+OpCapability Linkage
+OpMemoryModel Logical GLSL450
+%void = OpTypeVoid
+%bool = OpTypeBool
+%f32 = OpTypeFloat 32
+%image = OpTypeImage %f32 2D 0 0 0 1 Rgba32f
+%ptr_uc_image = OpTypePointer UniformConstant %image
+%image_var = OpVariable %ptr_uc_image UniformConstant
+%undef_bool = OpUndef %bool
+%undef_image = OpUndef %image
+%void_fn = OpTypeFunction %void
+%fn = OpFunction %void None %void_fn
+%entry = OpLabel
+%ld_image = OpLoad %image %image_var
+OpBranch %loop
+%loop = OpLabel
+%phi = OpPhi %image %undef_image %entry %ld_image %loop
+OpLoopMerge %exit %loop None
+OpBranchConditional %undef_bool %exit %loop
+%exit = OpLabel
+OpReturn
+OpFunctionEnd
+)";
+
+  CompileSuccessfully(text);
+  ASSERT_EQ(SPV_ERROR_INVALID_ID, ValidateInstructions());
+  EXPECT_THAT(getDiagnosticString(),
+              HasSubstr("Result type cannot be OpTypeImage"));
+}
+
+TEST_F(ValidateCFG, PhiResultInvalidSampledImage) {
+  const std::string text = R"(
+OpCapability Shader
+OpCapability Linkage
+OpMemoryModel Logical GLSL450
+%void = OpTypeVoid
+%bool = OpTypeBool
+%f32 = OpTypeFloat 32
+%sampler = OpTypeSampler
+%ptr_uc_sampler = OpTypePointer UniformConstant %sampler
+%sampler_var = OpVariable %ptr_uc_sampler UniformConstant
+%image = OpTypeImage %f32 2D 0 0 0 1 Rgba32f
+%ptr_uc_image = OpTypePointer UniformConstant %image
+%image_var = OpVariable %ptr_uc_image UniformConstant
+%sampled_image = OpTypeSampledImage %image
+%undef_bool = OpUndef %bool
+%undef_sampled_image = OpUndef %sampled_image
+%void_fn = OpTypeFunction %void
+%fn = OpFunction %void None %void_fn
+%entry = OpLabel
+%ld_image = OpLoad %image %image_var
+%ld_sampler = OpLoad %sampler %sampler_var
+OpBranch %loop
+%loop = OpLabel
+%phi = OpPhi %sampled_image %undef_sampled_image %entry %sample %loop
+%sample = OpSampledImage %sampled_image %ld_image %ld_sampler
+OpLoopMerge %exit %loop None
+OpBranchConditional %undef_bool %exit %loop
+%exit = OpLabel
+OpReturn
+OpFunctionEnd
+)";
+
+  CompileSuccessfully(text);
+  ASSERT_EQ(SPV_ERROR_INVALID_ID, ValidateInstructions());
+  EXPECT_THAT(getDiagnosticString(),
+              HasSubstr("Result type cannot be OpTypeSampledImage"));
+}
+
+TEST_F(ValidateCFG, PhiResultValidPreLegalizationSampler) {
+  const std::string text = R"(
+OpCapability Shader
+OpCapability Linkage
+OpMemoryModel Logical GLSL450
+%void = OpTypeVoid
+%bool = OpTypeBool
+%f32 = OpTypeFloat 32
+%sampler = OpTypeSampler
+%ptr_uc_sampler = OpTypePointer UniformConstant %sampler
+%sampler_var = OpVariable %ptr_uc_sampler UniformConstant
+%undef_bool = OpUndef %bool
+%undef_sampler = OpUndef %sampler
+%void_fn = OpTypeFunction %void
+%fn = OpFunction %void None %void_fn
+%entry = OpLabel
+%ld_sampler = OpLoad %sampler %sampler_var
+OpBranch %loop
+%loop = OpLabel
+%phi = OpPhi %sampler %undef_sampler %entry %ld_sampler %loop
+OpLoopMerge %exit %loop None
+OpBranchConditional %undef_bool %exit %loop
+%exit = OpLabel
+OpReturn
+OpFunctionEnd
+)";
+
+  options_->before_hlsl_legalization = true;
+  CompileSuccessfully(text);
+  ASSERT_EQ(SPV_SUCCESS, ValidateInstructions());
+}
+
+TEST_F(ValidateCFG, PhiResultValidPreLegalizationImage) {
+  const std::string text = R"(
+OpCapability Shader
+OpCapability Linkage
+OpMemoryModel Logical GLSL450
+%void = OpTypeVoid
+%bool = OpTypeBool
+%f32 = OpTypeFloat 32
+%image = OpTypeImage %f32 2D 0 0 0 1 Rgba32f
+%ptr_uc_image = OpTypePointer UniformConstant %image
+%image_var = OpVariable %ptr_uc_image UniformConstant
+%undef_bool = OpUndef %bool
+%undef_image = OpUndef %image
+%void_fn = OpTypeFunction %void
+%fn = OpFunction %void None %void_fn
+%entry = OpLabel
+%ld_image = OpLoad %image %image_var
+OpBranch %loop
+%loop = OpLabel
+%phi = OpPhi %image %undef_image %entry %ld_image %loop
+OpLoopMerge %exit %loop None
+OpBranchConditional %undef_bool %exit %loop
+%exit = OpLabel
+OpReturn
+OpFunctionEnd
+)";
+
+  options_->before_hlsl_legalization = true;
+  CompileSuccessfully(text);
+  ASSERT_EQ(SPV_SUCCESS, ValidateInstructions());
+}
+
+TEST_F(ValidateCFG, PhiResultValidPreLegalizationSampledImage) {
+  const std::string text = R"(
+OpCapability Shader
+OpCapability Linkage
+OpMemoryModel Logical GLSL450
+%void = OpTypeVoid
+%bool = OpTypeBool
+%f32 = OpTypeFloat 32
+%sampler = OpTypeSampler
+%ptr_uc_sampler = OpTypePointer UniformConstant %sampler
+%sampler_var = OpVariable %ptr_uc_sampler UniformConstant
+%image = OpTypeImage %f32 2D 0 0 0 1 Rgba32f
+%ptr_uc_image = OpTypePointer UniformConstant %image
+%image_var = OpVariable %ptr_uc_image UniformConstant
+%sampled_image = OpTypeSampledImage %image
+%undef_bool = OpUndef %bool
+%undef_sampled_image = OpUndef %sampled_image
+%void_fn = OpTypeFunction %void
+%fn = OpFunction %void None %void_fn
+%entry = OpLabel
+%ld_image = OpLoad %image %image_var
+%ld_sampler = OpLoad %sampler %sampler_var
+OpBranch %loop
+%loop = OpLabel
+%phi = OpPhi %sampled_image %undef_sampled_image %entry %sample %loop
+%sample = OpSampledImage %sampled_image %ld_image %ld_sampler
+OpLoopMerge %exit %loop None
+OpBranchConditional %undef_bool %exit %loop
+%exit = OpLabel
+OpReturn
+OpFunctionEnd
+)";
+
+  options_->before_hlsl_legalization = true;
+  CompileSuccessfully(text);
+  ASSERT_EQ(SPV_SUCCESS, ValidateInstructions());
+}
+
 }  // namespace
 }  // namespace val
 }  // namespace spvtools