diff --git a/SPIRV/GlslangToSpv.cpp b/SPIRV/GlslangToSpv.cpp
index 9d42e3c..c174375 100755
--- a/SPIRV/GlslangToSpv.cpp
+++ b/SPIRV/GlslangToSpv.cpp
@@ -110,6 +110,7 @@
     spv::Id createBinaryOperation(glslang::TOperator op, spv::Decoration precision, spv::Id typeId, spv::Id left, spv::Id right, glslang::TBasicType typeProxy, bool reduceComparison = true);
     spv::Id createBinaryMatrixOperation(spv::Op, spv::Decoration precision, spv::Id typeId, spv::Id left, spv::Id right);
     spv::Id createUnaryOperation(glslang::TOperator op, spv::Decoration precision, spv::Id typeId, spv::Id operand,glslang::TBasicType typeProxy);
+    spv::Id createUnaryMatrixOperation(spv::Op, spv::Decoration precision, spv::Id typeId, spv::Id operand,glslang::TBasicType typeProxy);
     spv::Id createConversion(glslang::TOperator op, spv::Decoration precision, spv::Id destTypeId, spv::Id operand);
     spv::Id makeSmearedConstant(spv::Id constant, int vectorSize);
     spv::Id createAtomicOperation(glslang::TOperator op, spv::Decoration precision, spv::Id typeId, std::vector<spv::Id>& operands, glslang::TBasicType typeProxy);
@@ -2601,9 +2602,11 @@
 
     switch (op) {
     case glslang::EOpNegative:
-        if (isFloat)
+        if (isFloat) {
             unaryOp = spv::OpFNegate;
-        else
+            if (builder.isMatrixType(typeId))
+                return createUnaryMatrixOperation(unaryOp, precision, typeId, operand, typeProxy);
+        } else
             unaryOp = spv::OpSNegate;
         break;
 
@@ -2862,6 +2865,39 @@
     return id;
 }
 
+// Create a unary operation on a matrix
+spv::Id TGlslangToSpvTraverser::createUnaryMatrixOperation(spv::Op op, spv::Decoration precision, spv::Id typeId, spv::Id operand, glslang::TBasicType /* typeProxy */)
+{
+    // Handle unary operations vector by vector.
+    // The result type is the same type as the original type.
+    // The algorithm is to:
+    //   - break the matrix into vectors
+    //   - apply the operation to each vector
+    //   - make a matrix out the vector results
+
+    // get the types sorted out
+    int numCols = builder.getNumColumns(operand);
+    int numRows = builder.getNumRows(operand);
+    spv::Id scalarType = builder.getScalarTypeId(typeId);
+    spv::Id vecType = builder.makeVectorType(scalarType, numRows);
+    std::vector<spv::Id> results;
+
+    // do each vector op
+    for (int c = 0; c < numCols; ++c) {
+        std::vector<unsigned int> indexes;
+        indexes.push_back(c);
+        spv::Id vec =  builder.createCompositeExtract(operand, vecType, indexes);
+        results.push_back(builder.createUnaryOp(op, vecType, vec));
+        builder.setPrecision(results.back(), precision);
+    }
+
+    // put the pieces together
+    spv::Id id = builder.createCompositeConstruct(typeId, results);
+    builder.setPrecision(id, precision);
+
+    return id;
+}
+
 spv::Id TGlslangToSpvTraverser::createConversion(glslang::TOperator op, spv::Decoration precision, spv::Id destType, spv::Id operand)
 {
     spv::Op convOp = spv::OpNop;