diff --git a/source/val/validate_function.cpp b/source/val/validate_function.cpp
index 799ba3d54..39f00fedc 100644
--- a/source/val/validate_function.cpp
+++ b/source/val/validate_function.cpp
@@ -14,6 +14,8 @@
 
 #include "source/val/validate.h"
 
+#include <algorithm>
+
 #include "source/opcode.h"
 #include "source/val/instruction.h"
 #include "source/val/validation_state.h"
@@ -38,6 +40,27 @@ spv_result_t ValidateFunction(ValidationState_t& _, const Instruction* inst) {
            << "' does not match the Function Type's return type <id> '"
            << _.getIdName(return_id) << "'.";
   }
+
+  for (auto& pair : inst->uses()) {
+    const auto* use = pair.first;
+    const std::vector<SpvOp> acceptable = {
+        SpvOpFunctionCall,
+        SpvOpEntryPoint,
+        SpvOpEnqueueKernel,
+        SpvOpGetKernelNDrangeSubGroupCount,
+        SpvOpGetKernelNDrangeMaxSubGroupSize,
+        SpvOpGetKernelWorkGroupSize,
+        SpvOpGetKernelPreferredWorkGroupSizeMultiple,
+        SpvOpGetKernelLocalSizeForSubgroupCount,
+        SpvOpGetKernelMaxNumSubgroups};
+    if (std::find(acceptable.begin(), acceptable.end(), use->opcode()) ==
+        acceptable.end()) {
+      return _.diag(SPV_ERROR_INVALID_ID, use)
+             << "Invalid use of function result id " << _.getIdName(inst->id())
+             << ".";
+    }
+  }
+
   return SPV_SUCCESS;
 }
 
diff --git a/test/val/val_cfg_test.cpp b/test/val/val_cfg_test.cpp
index 14d098dd2..045166925 100644
--- a/test/val/val_cfg_test.cpp
+++ b/test/val/val_cfg_test.cpp
@@ -477,9 +477,10 @@ TEST_P(ValidateCFG, BranchTargetFirstBlockBadSinceEntryBlock) {
 
 TEST_P(ValidateCFG, BranchTargetFirstBlockBadSinceValue) {
   Block entry("entry");
+  entry.SetBody("%undef = OpUndef %voidt\n");
   Block bad("bad");
   Block end("end", SpvOpReturn);
-  Block badvalue("func");  // This referenes the function name.
+  Block badvalue("undef");  // This referenes the OpUndef.
   std::string str = header(GetParam()) +
                     nameOps("entry", "bad", std::make_pair("func", "Main")) +
                     types_consts() +
@@ -493,11 +494,10 @@ TEST_P(ValidateCFG, BranchTargetFirstBlockBadSinceValue) {
 
   CompileSuccessfully(str);
   ASSERT_EQ(SPV_ERROR_INVALID_CFG, ValidateInstructions());
-  EXPECT_THAT(
-      getDiagnosticString(),
-      MatchesRegex("Block\\(s\\) \\{.\\[Main\\]\\} are referenced but not "
-                   "defined in function .\\[Main\\]\n"
-                   "  %Main = OpFunction %void None %10\n"))
+  EXPECT_THAT(getDiagnosticString(),
+              MatchesRegex("Block\\(s\\) \\{..\\} are referenced but not "
+                           "defined in function .\\[Main\\]\n"
+                           "  %Main = OpFunction %void None %10\n"))
       << str;
 }
 
diff --git a/test/val/val_id_test.cpp b/test/val/val_id_test.cpp
index c0d865331..eee503d62 100644
--- a/test/val/val_id_test.cpp
+++ b/test/val/val_id_test.cpp
@@ -2192,13 +2192,14 @@ TEST_F(ValidateIdWithMessage, OpStoreObjectGood) {
 %6 = OpVariable %3 UniformConstant
 %7 = OpFunction %1 None %4
 %8 = OpLabel
-     OpStore %6 %7
+%9 = OpUndef %1
+     OpStore %6 %9
      OpReturn
      OpFunctionEnd)";
   CompileSuccessfully(spirv.c_str());
   EXPECT_EQ(SPV_ERROR_INVALID_ID, ValidateInstructions());
   EXPECT_THAT(getDiagnosticString(),
-              HasSubstr("OpStore Object <id> '7's type is void."));
+              HasSubstr("OpStore Object <id> '9's type is void."));
 }
 TEST_F(ValidateIdWithMessage, OpStoreTypeBad) {
   std::string spirv = kGLSL450MemoryModel + R"(
@@ -3577,6 +3578,22 @@ OpFunctionEnd)";
       HasSubstr("OpFunction Function Type <id> '2' is not a function type."));
 }
 
+TEST_F(ValidateIdWithMessage, OpFunctionUseBad) {
+  const std::string spirv = kGLSL450MemoryModel + R"(
+%1 = OpTypeFloat 32
+%2 = OpTypeFunction %1
+%3 = OpFunction %1 None %2
+%4 = OpLabel
+OpReturnValue %3
+OpFunctionEnd
+)";
+
+  CompileSuccessfully(spirv);
+  EXPECT_EQ(SPV_ERROR_INVALID_ID, ValidateInstructions());
+  EXPECT_THAT(getDiagnosticString(),
+              HasSubstr("Invalid use of function result id 3."));
+}
+
 TEST_F(ValidateIdWithMessage, OpFunctionParameterGood) {
   std::string spirv = kGLSL450MemoryModel + R"(
 %1 = OpTypeVoid