diff --git a/src/codegen/x86_64/CodeGen.zig b/src/codegen/x86_64/CodeGen.zig
index 8dc2a26f5a923644ee0c514863b8534c35f43da9..32c6552f78b51d0b0212908521bf08acdd3b0d3c 100644
--- a/src/codegen/x86_64/CodeGen.zig
+++ b/src/codegen/x86_64/CodeGen.zig
@@ -176662,7 +176662,7 @@ fn lowerSwitchBr(
             };
             const condition_index_lock = cg.register_manager.lockReg(condition_index_reg);
             defer if (condition_index_lock) |lock| cg.register_manager.unlockReg(lock);
-            try cg.truncateRegister(condition_ty, condition_index_reg);
+            try cg.truncateRegister(unsigned_condition_ty, condition_index_reg);
             const ptr_size = @divExact(cg.target.ptrBitWidth(), 8);
             try cg.asmMemory(.{ ._mp, .j }, .{
                 .base = .table,
diff --git a/test/behavior/enum.zig b/test/behavior/enum.zig
index 6557de08ca9dd687b2231436b3d48bf96e0dbbde..c9bdf8a5b09829f67165c09d71018b3602cafed9 100644
--- a/test/behavior/enum.zig
+++ b/test/behavior/enum.zig
@@ -1313,6 +1313,24 @@ test "switch on an extern enum with negative value" {
     }
 }
 
+test "switch on an enum with small signed tag type" {
+    const E = enum(i3) {
+        y = -2,
+        z = -1,
+        a = 0,
+        b = 1,
+        c = 2,
+    };
+
+    var runtime: E = .c;
+    _ = &runtime;
+    const result: u8 = switch (runtime) {
+        .y, .z, .a, .b => 0,
+        .c => 1,
+    };
+    try expect(result == 1);
+}
+
 test "Non-exhaustive enum with nonstandard int size behaves correctly" {
     const E = enum(u15) { _ };
     try expect(@sizeOf(E) == @sizeOf(u15));