diff --git a/renderdoc/driver/shaders/spirv/spirv_debug.cpp b/renderdoc/driver/shaders/spirv/spirv_debug.cpp
index da5ab07d3..52f9e9ec1 100644
--- a/renderdoc/driver/shaders/spirv/spirv_debug.cpp
+++ b/renderdoc/driver/shaders/spirv/spirv_debug.cpp
@@ -1147,6 +1147,27 @@ void ThreadState::StepNext(ShaderDebugState *state,
       SetDst(state, math.result, var);
       break;
     }
+    case Op::FNegate:
+    case Op::SNegate:
+    {
+      OpFNegate math(it);
+
+      ShaderVariable var = GetSrc(math.operand);
+
+      if(opdata.op == Op::FNegate)
+      {
+        for(uint8_t c = 0; c < var.columns; c++)
+          var.value.fv[c] = -var.value.fv[c];
+      }
+      else if(opdata.op == Op::SNegate)
+      {
+        for(uint8_t c = 0; c < var.columns; c++)
+          var.value.iv[c] = -var.value.iv[c];
+      }
+
+      SetDst(state, math.result, var);
+      break;
+    }
 
     //////////////////////////////////////////////////////////////////////////////
     //
diff --git a/util/test/demos/vk/vk_shader_debug_zoo.cpp b/util/test/demos/vk/vk_shader_debug_zoo.cpp
index f25e5a191..99c1c9048 100644
--- a/util/test/demos/vk/vk_shader_debug_zoo.cpp
+++ b/util/test/demos/vk/vk_shader_debug_zoo.cpp
@@ -407,6 +407,8 @@ void main()
                         16 %test_16
                         17 %test_17
                         18 %test_18
+                        19 %test_19
+                        20 %test_20
 
      ; test OpVectorShuffle
      %test_0 = OpLabel
@@ -565,6 +567,38 @@ void main()
                OpStore %Color %Color_18
                OpBranch %break
 
+     ; test fnegate
+    %test_19 = OpLabel
+       %a_19 = OpFAdd %float %zerof %float_4
+       %b_19 = OpFAdd %float %zerof %float_neg15
+       %c_19 = OpFAdd %float %zerof %zerof
+       %d_19 = OpFAdd %float %zerof %float_3
+       %x_19 = OpFNegate %float %a_19
+       %y_19 = OpFNegate %float %b_19
+       %z_19 = OpFNegate %float %c_19
+       %w_19 = OpFNegate %float %d_19
+   %Color_19 = OpCompositeConstruct %float4 %x_19 %y_19 %z_19 %w_19
+               OpStore %Color %Color_19
+               OpBranch %break
+
+     ; test snegate
+    %test_20 = OpLabel
+       %a_20 = OpIAdd %int %zeroi %int_4
+       %b_20 = OpIAdd %int %zeroi %int_neg15
+       %c_20 = OpIAdd %int %zeroi %zeroi
+       %d_20 = OpIAdd %int %zeroi %int_7
+       %x_20 = OpSNegate %int %a_20
+       %y_20 = OpSNegate %int %b_20
+       %z_20 = OpSNegate %int %c_20
+       %w_20 = OpSNegate %int %d_20
+      %xf_20 = OpConvertSToF %float %x_20
+      %yf_20 = OpConvertSToF %float %y_20
+      %zf_20 = OpConvertSToF %float %z_20
+      %wf_20 = OpConvertSToF %float %w_20
+   %Color_20 = OpCompositeConstruct %float4 %xf_20 %yf_20 %zf_20 %wf_20
+               OpStore %Color %Color_20
+               OpBranch %break
+
     %default = OpLabel
                OpStore %Color %float_0000
                OpBranch %break