diff --git a/SPIRV/GlslangToSpv.h b/SPIRV/GlslangToSpv.h
index 11e22f58..aba48a38 100644
--- a/SPIRV/GlslangToSpv.h
+++ b/SPIRV/GlslangToSpv.h
@@ -32,6 +32,8 @@
 // ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 // POSSIBILITY OF SUCH DAMAGE.
 
+#pragma once
+
 #if _MSC_VER >= 1900
     #pragma warning(disable : 4464) // relative include path contains '..'
 #endif
diff --git a/SPIRV/doc.h b/SPIRV/doc.h
index 7dcc51dd..710ca1a5 100644
--- a/SPIRV/doc.h
+++ b/SPIRV/doc.h
@@ -36,6 +36,8 @@
 // Parameterize the SPIR-V enumerants.
 //
 
+#pragma once
+
 #include "spirv.hpp"
 
 #include <vector>
diff --git a/glslang/MachineIndependent/LiveTraverser.h b/glslang/MachineIndependent/LiveTraverser.h
index 029c24a8..7333bc96 100644
--- a/glslang/MachineIndependent/LiveTraverser.h
+++ b/glslang/MachineIndependent/LiveTraverser.h
@@ -33,6 +33,8 @@
 // POSSIBILITY OF SUCH DAMAGE.
 //
 
+#pragma once
+
 #include "../Include/Common.h"
 #include "reflection.h"
 #include "localintermediate.h"
diff --git a/glslang/MachineIndependent/RemoveTree.h b/glslang/MachineIndependent/RemoveTree.h
index 507307e4..1ed01562 100644
--- a/glslang/MachineIndependent/RemoveTree.h
+++ b/glslang/MachineIndependent/RemoveTree.h
@@ -32,6 +32,8 @@
 // POSSIBILITY OF SUCH DAMAGE.
 //
 
+#pragma once
+
 namespace glslang {
 
 void RemoveAllTreeNodes(TIntermNode*);
diff --git a/glslang/MachineIndependent/ScanContext.h b/glslang/MachineIndependent/ScanContext.h
index 1d86348e..608ae067 100644
--- a/glslang/MachineIndependent/ScanContext.h
+++ b/glslang/MachineIndependent/ScanContext.h
@@ -38,6 +38,8 @@
 // sits between the preprocessor scanner and parser.
 //
 
+#pragma once
+
 #include "ParseHelper.h"
 
 namespace glslang {
diff --git a/glslang/MachineIndependent/gl_types.h b/glslang/MachineIndependent/gl_types.h
index d7cb31fe..ae00ae57 100644
--- a/glslang/MachineIndependent/gl_types.h
+++ b/glslang/MachineIndependent/gl_types.h
@@ -21,6 +21,8 @@
 ** MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
 */
 
+#pragma once
+
 #define GL_FLOAT                          0x1406
 #define GL_FLOAT_VEC2                     0x8B50
 #define GL_FLOAT_VEC3                     0x8B51
diff --git a/glslang/MachineIndependent/propagateNoContraction.h b/glslang/MachineIndependent/propagateNoContraction.h
index 3412c85d..8521ad7d 100644
--- a/glslang/MachineIndependent/propagateNoContraction.h
+++ b/glslang/MachineIndependent/propagateNoContraction.h
@@ -37,6 +37,8 @@
 // propagate 'noContraction' qualifier.
 //
 
+#pragma once
+
 #include "../Include/intermediate.h"
 
 namespace glslang {