diff --git a/src/gallium/drivers/d3d12/d3d12_context.cpp b/src/gallium/drivers/d3d12/d3d12_context.cpp
index ecfaa41139c..39cdcab2cde 100644
--- a/src/gallium/drivers/d3d12/d3d12_context.cpp
+++ b/src/gallium/drivers/d3d12/d3d12_context.cpp
@@ -904,6 +904,8 @@ d3d12_create_sampler_view(struct pipe_context *pctx,
       desc.Buffer.StructureByteStride = 0;
       desc.Buffer.NumElements = texture->width0 / util_format_get_blocksize(state->format);
       break;
+   default:
+      unreachable("Invalid SRV dimension");
    }
 
    d3d12_descriptor_pool_alloc_handle(ctx->view_pool, &sampler_view->handle);
diff --git a/src/gallium/drivers/d3d12/d3d12_format.c b/src/gallium/drivers/d3d12/d3d12_format.c
index 5bf4e6110bf..89a617a6dd7 100644
--- a/src/gallium/drivers/d3d12/d3d12_format.c
+++ b/src/gallium/drivers/d3d12/d3d12_format.c
@@ -285,9 +285,10 @@ d3d12_non_opaque_plane_count(DXGI_FORMAT format)
    case DXGI_FORMAT_Y216:
    case DXGI_FORMAT_NV11:
       return 2;
-   }
 
-   return 1;
+   default:
+      return 1;
+   }
 }
 
 unsigned
diff --git a/src/gallium/drivers/d3d12/d3d12_resource.cpp b/src/gallium/drivers/d3d12/d3d12_resource.cpp
index 2dd9787a470..1917076976b 100644
--- a/src/gallium/drivers/d3d12/d3d12_resource.cpp
+++ b/src/gallium/drivers/d3d12/d3d12_resource.cpp
@@ -172,6 +172,9 @@ init_texture(struct d3d12_screen *screen,
       desc.Dimension = D3D12_RESOURCE_DIMENSION_TEXTURE3D;
       desc.DepthOrArraySize = templ->depth0;
       break;
+
+   default:
+      unreachable("Invalid texture type");
    }
 
    desc.Flags = D3D12_RESOURCE_FLAG_NONE;
diff --git a/src/gallium/drivers/d3d12/d3d12_screen.cpp b/src/gallium/drivers/d3d12/d3d12_screen.cpp
index f273e559d87..5241e9f1ac9 100644
--- a/src/gallium/drivers/d3d12/d3d12_screen.cpp
+++ b/src/gallium/drivers/d3d12/d3d12_screen.cpp
@@ -475,10 +475,10 @@ d3d12_get_shader_param(struct pipe_screen *pscreen,
    case PIPE_SHADER_CAP_MAX_HW_ATOMIC_COUNTER_BUFFERS:
    case PIPE_SHADER_CAP_TGSI_CONT_SUPPORTED:
       return 0; /* not implemented */
-   }
 
    /* should only get here on unhandled cases */
-   return 0;
+   default: return 0;
+   }
 }
 
 static bool
diff --git a/src/gallium/drivers/d3d12/d3d12_surface.cpp b/src/gallium/drivers/d3d12/d3d12_surface.cpp
index 8cd7623ee3e..48f4818e69f 100644
--- a/src/gallium/drivers/d3d12/d3d12_surface.cpp
+++ b/src/gallium/drivers/d3d12/d3d12_surface.cpp
@@ -134,6 +134,9 @@ initialize_dsv(struct pipe_context *pctx,
       desc.Texture2DArray.FirstArraySlice = tpl->u.tex.first_layer;
       desc.Texture2DArray.ArraySize = tpl->u.tex.last_layer - tpl->u.tex.first_layer + 1;
       break;
+
+   default:
+      unreachable("Unhandled DSV dimension");
    }
 
    d3d12_descriptor_pool_alloc_handle(ctx->dsv_pool, handle);
@@ -208,6 +211,9 @@ initialize_rtv(struct pipe_context *pctx,
       desc.Texture3D.FirstWSlice = tpl->u.tex.first_layer;
       desc.Texture3D.WSize = tpl->u.tex.last_layer - tpl->u.tex.first_layer + 1;
       break;
+
+   default:
+      unreachable("Unhandled RTV dimension");
    }
 
    d3d12_descriptor_pool_alloc_handle(ctx->rtv_pool, handle);