diff --git a/stage0/sema.c b/stage0/sema.c
index 1646886d70..8ad7c9836f 100644
--- a/stage0/sema.c
+++ b/stage0/sema.c
@@ -1198,11 +1198,28 @@ static AirInstRef zirAbs(Sema* sema, SemaBlock* block, uint32_t inst) {
     AirInstRef operand = resolveInst(sema, operand_ref);
     TypeIndex operand_ty = semaTypeOf(sema, operand);
 
-    // For floats, result type is the same as operand type.
-    // Emit AIR_INST_ABS as ty_op.
+    TypeIndex result_ty = operand_ty;
+    if (sema->ip->items[operand_ty].tag == IP_KEY_INT_TYPE) {
+        if (!sema->ip->items[operand_ty].data.int_type.signedness) {
+            // Unsigned int: @abs is identity.
+            // Ported from src/Sema.zig zirAbs: `.int => if (signed) toUnsigned
+            // else return operand`
+            return operand;
+        }
+        // Signed int: result type is the unsigned equivalent.
+        // Ported from src/Sema.zig operand_ty.toUnsigned(pt).
+        InternPoolKey key;
+        memset(&key, 0, sizeof(key));
+        key.tag = IP_KEY_INT_TYPE;
+        key.data.int_type.bits
+            = sema->ip->items[operand_ty].data.int_type.bits;
+        key.data.int_type.signedness = false;
+        result_ty = ipIntern(sema->ip, key);
+    }
+
     AirInstData data;
     memset(&data, 0, sizeof(data));
-    data.ty_op.ty_ref = AIR_REF_FROM_IP(operand_ty);
+    data.ty_op.ty_ref = AIR_REF_FROM_IP(result_ty);
     data.ty_op.operand = operand;
     return semaAddInst(block, AIR_INST_ABS, data);
 }