diff --git a/src/stage1/codegen.cpp b/src/stage1/codegen.cpp
index c575aff53d..9d46a660bc 100644
--- a/src/stage1/codegen.cpp
+++ b/src/stage1/codegen.cpp
@@ -9586,10 +9586,13 @@ static void define_builtin_types(CodeGen *g) {
     switch (g->zig_target->arch) {
         case ZigLLVM_x86:
         case ZigLLVM_x86_64:
-            if (g->zig_target->abi != ZigLLVM_MSVC)
+            if (g->zig_target->abi != ZigLLVM_MSVC) {
                 add_fp_entry(g, "c_longdouble", 80, LLVMX86FP80Type(), &g->builtin_types.entry_c_longdouble);
-            else
+                g->builtin_types.entry_c_longdouble->abi_size = g->builtin_types.entry_f80->abi_size;
+                g->builtin_types.entry_c_longdouble->abi_align = g->builtin_types.entry_f80->abi_align;
+            } else {
                 add_fp_entry(g, "c_longdouble", 64, LLVMDoubleType(), &g->builtin_types.entry_c_longdouble);
+            }
             break;
         case ZigLLVM_arm:
         case ZigLLVM_armeb:
diff --git a/test/behavior/math.zig b/test/behavior/math.zig
index 85cf7f5643..0479015eee 100644
--- a/test/behavior/math.zig
+++ b/test/behavior/math.zig
@@ -1416,12 +1416,6 @@ test "fabs" {
     if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
 
-    if (builtin.zig_backend == .stage1 and builtin.os.tag == .windows and
-        builtin.cpu.arch == .i386)
-    {
-        return error.SkipZigTest;
-    }
-
     inline for ([_]type{ f16, f32, f64, f80, f128, c_longdouble }) |T| {
         // normals
         try expect(@fabs(@as(T, 1.0)) == 1.0);