diff --git a/test/behavior/align.zig b/test/behavior/align.zig
index a59bed56ba..550d7008b4 100644
--- a/test/behavior/align.zig
+++ b/test/behavior/align.zig
@@ -18,6 +18,7 @@ test "global variable alignment" {
 test "large alignment of local constant" {
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_spirv) return error.SkipZigTest; // flaky
+    if (builtin.zig_backend == .stage2_c and builtin.target.abi == .msvc) return error.SkipZigTest;
 
     const x: f32 align(128) = 12.34;
     try std.testing.expect(@intFromPtr(&x) % 128 == 0);
diff --git a/test/behavior/union.zig b/test/behavior/union.zig
index 9badc9dabd..faa3f42ea5 100644
--- a/test/behavior/union.zig
+++ b/test/behavior/union.zig
@@ -148,6 +148,7 @@ const err = @as(anyerror!Agg, Agg{
 const array = [_]Value{ v1, v2, v1, v2 };
 
 test "unions embedded in aggregate types" {
+    if (builtin.zig_backend == .stage2_c and builtin.target.abi == .msvc) return error.SkipZigTest;
     switch (array[1]) {
         Value.Array => |arr| try expect(arr[4] == 3),
         else => unreachable,
@@ -2022,6 +2023,7 @@ test "runtime union init, most-aligned field != largest" {
     if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_spirv) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_riscv64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_c and builtin.target.abi == .msvc) return error.SkipZigTest;
 
     const U = union(enum) {
         x: u128,