diff --git a/include/spirv/unified1/spirv.h b/include/spirv/unified1/spirv.h
index ba1c998..2b6b35f 100644
--- a/include/spirv/unified1/spirv.h
+++ b/include/spirv/unified1/spirv.h
@@ -1856,6 +1856,9 @@ typedef enum SpvOp_ {
 } SpvOp;
 
 #ifdef SPV_ENABLE_UTILITY_CODE
+#ifndef __cplusplus
+#include <stdbool.h>
+#endif
 inline void SpvHasResultAndType(SpvOp opcode, bool *hasResult, bool *hasResultType) {
     *hasResult = *hasResultType = false;
     switch (opcode) {
diff --git a/include/spirv/unified1/spirv.hpp b/include/spirv/unified1/spirv.hpp
index a016d7d..08eae15 100644
--- a/include/spirv/unified1/spirv.hpp
+++ b/include/spirv/unified1/spirv.hpp
@@ -1852,6 +1852,9 @@ enum Op {
 };
 
 #ifdef SPV_ENABLE_UTILITY_CODE
+#ifndef __cplusplus
+#include <stdbool.h>
+#endif
 inline void HasResultAndType(Op opcode, bool *hasResult, bool *hasResultType) {
     *hasResult = *hasResultType = false;
     switch (opcode) {
diff --git a/include/spirv/unified1/spirv.hpp11 b/include/spirv/unified1/spirv.hpp11
index 89d793c..d203289 100644
--- a/include/spirv/unified1/spirv.hpp11
+++ b/include/spirv/unified1/spirv.hpp11
@@ -1852,6 +1852,9 @@ enum class Op : unsigned {
 };
 
 #ifdef SPV_ENABLE_UTILITY_CODE
+#ifndef __cplusplus
+#include <stdbool.h>
+#endif
 inline void HasResultAndType(Op opcode, bool *hasResult, bool *hasResultType) {
     *hasResult = *hasResultType = false;
     switch (opcode) {
diff --git a/tools/buildHeaders/header.cpp b/tools/buildHeaders/header.cpp
index febc6f2..f2f16b3 100644
--- a/tools/buildHeaders/header.cpp
+++ b/tools/buildHeaders/header.cpp
@@ -513,6 +513,9 @@ namespace {
                 }
 
                 out << "#ifdef SPV_ENABLE_UTILITY_CODE" << std::endl;
+                out << "#ifndef __cplusplus" << std::endl;
+                out << "#include <stdbool.h>" << std::endl;
+                out << "#endif" << std::endl;
                 out << "inline void " << pre() << "HasResultAndType(" << pre() << opName << " opcode, bool *hasResult, bool *hasResultType) {" << std::endl;
                 out << "    *hasResult = *hasResultType = false;" << std::endl;
                 out << "    switch (opcode) {" << std::endl;