diff --git a/xc7/arch.cc b/xc7/arch.cc
index df21c208..764d2231 100644
--- a/xc7/arch.cc
+++ b/xc7/arch.cc
@@ -67,6 +67,8 @@ std::vector<IdString> TorcInfo::construct_site_index_to_type(Arch* ctx, const Si
         const auto &type = pd->getName();
         if (type == "SLICEL" || type == "SLICEM")
             site_index_to_type[i] = id_SLICE_LUT6;
+        else if (type == "IOB33S" || type == "IOB33M")
+            site_index_to_type[i] = id_IOB;
         else
             site_index_to_type[i] = ctx->id(type);
     }
@@ -788,7 +790,7 @@ TimingPortClass Arch::getPortTimingClass(const CellInfo *cell, IdString port, Id
         // TODO
         //if (port == id_OMUX)
     }
-    else if (cell->type == id_IOB33S) {
+    else if (cell->type == id_IOB) {
         if (port == id_I)
             return TMG_STARTPOINT;
         else if (port == id_O)
diff --git a/xc7/cells.cc b/xc7/cells.cc
index f5f23f5a..dbdc4b82 100644
--- a/xc7/cells.cc
+++ b/xc7/cells.cc
@@ -70,7 +70,7 @@ std::unique_ptr<CellInfo> create_ice_cell(Context *ctx, IdString type, std::stri
         add_port(ctx, new_cell.get(), "OMUX", PORT_OUT);
         add_port(ctx, new_cell.get(), "COUT", PORT_OUT);
     } else if (type == ctx->id("IOBUF")) {
-        new_cell->type = id_IOB33S;
+        new_cell->type = id_IOB;
         new_cell->params[ctx->id("PIN_TYPE")] = "0";
         new_cell->params[ctx->id("PULLUP")] = "0";
         new_cell->params[ctx->id("NEG_TRIGGER")] = "0";
diff --git a/xc7/constids.inc b/xc7/constids.inc
index 8e07efd9..c760bdb0 100644
--- a/xc7/constids.inc
+++ b/xc7/constids.inc
@@ -456,6 +456,4 @@ X(FDPE)
 
 X(BUFGCTRL)
 X(SLICE_LUT6)
-X(IOBUF)
-X(IOB33S)
-X(IOB33M) // What is the difference between IOB33S and IOB33M?
+X(IOB)
diff --git a/xc7/xdl.cc b/xc7/xdl.cc
index f2aed473..3fa20d5a 100644
--- a/xc7/xdl.cc
+++ b/xc7/xdl.cc
@@ -54,7 +54,7 @@ void write_xdl(const Context *ctx, std::ostream &out)
     for (const auto& cell : ctx->cells) {
         const char* type;
         if (cell.second->type == id_SLICE_LUT6) type = "SLICEL";
-        else if (cell.second->type == id_IOB33S) type = "IOB33S";
+        else if (cell.second->type == id_IOB) type = "IOB33S";
         else if (cell.second->type == id_BUFGCTRL) type = "BUFGCTRL";
         else log_error("Unsupported cell type '%s'.\n", cell.second->type.c_str(ctx));
 
@@ -141,7 +141,7 @@ void write_xdl(const Context *ctx, std::ostream &out)
                 instPtr->setConfig(setting, name, "#FF");
             }
         }
-        else if (cell.second->type == id_IOB33S) {
+        else if (cell.second->type == id_IOB) {
             if (get_net_or_empty(cell.second.get(), id_I)) {
                 instPtr->setConfig("IUSED", "", "0");
                 instPtr->setConfig("IBUF_LOW_PWR", "", "TRUE");