diff --git a/src/compiler/nir/tests/builder_tests.cpp b/src/compiler/nir/tests/builder_tests.cpp
index c897eb1de97..244057dd1d9 100644
--- a/src/compiler/nir/tests/builder_tests.cpp
+++ b/src/compiler/nir/tests/builder_tests.cpp
@@ -67,19 +67,16 @@ protected:
 
    std::vector<nir_intrinsic_instr *> stores;
 
-   void *mem_ctx;
-
-   nir_builder *b;
+   nir_builder *b, _b;
 };
 
 nir_builder_test::nir_builder_test()
 {
    glsl_type_singleton_init_or_ref();
 
-   mem_ctx = ralloc_context(NULL);
    static const nir_shader_compiler_options options = { };
-   b = rzalloc(mem_ctx, nir_builder);
-   *b = nir_builder_init_simple_shader(mem_ctx, MESA_SHADER_COMPUTE, &options);
+   _b = nir_builder_init_simple_shader(NULL, MESA_SHADER_COMPUTE, &options);
+   b = &_b;
 }
 
 nir_builder_test::~nir_builder_test()
@@ -89,7 +86,7 @@ nir_builder_test::~nir_builder_test()
       nir_print_shader(b->shader, stdout);
    }
 
-   ralloc_free(mem_ctx);
+   ralloc_free(b->shader);
 
    glsl_type_singleton_decref();
 }
diff --git a/src/compiler/nir/tests/load_store_vectorizer_tests.cpp b/src/compiler/nir/tests/load_store_vectorizer_tests.cpp
index b16b630e864..7d98ca2a808 100644
--- a/src/compiler/nir/tests/load_store_vectorizer_tests.cpp
+++ b/src/compiler/nir/tests/load_store_vectorizer_tests.cpp
@@ -78,9 +78,7 @@ protected:
 
    std::string swizzle(nir_alu_instr *instr, int src);
 
-   void *mem_ctx;
-
-   nir_builder *b;
+   nir_builder *b, _b;
    std::map<unsigned, nir_alu_instr*> movs;
    std::map<unsigned, nir_alu_src*> loads;
    std::map<unsigned, nir_ssa_def*> res_map;
@@ -90,10 +88,9 @@ nir_load_store_vectorize_test::nir_load_store_vectorize_test()
 {
    glsl_type_singleton_init_or_ref();
 
-   mem_ctx = ralloc_context(NULL);
    static const nir_shader_compiler_options options = { };
-   b = rzalloc(mem_ctx, nir_builder);
-   *b = nir_builder_init_simple_shader(mem_ctx, MESA_SHADER_COMPUTE, &options);
+   _b = nir_builder_init_simple_shader(NULL, MESA_SHADER_COMPUTE, &options);
+   b = &_b;
 }
 
 nir_load_store_vectorize_test::~nir_load_store_vectorize_test()
@@ -103,7 +100,7 @@ nir_load_store_vectorize_test::~nir_load_store_vectorize_test()
       nir_print_shader(b->shader, stdout);
    }
 
-   ralloc_free(mem_ctx);
+   ralloc_free(b->shader);
 
    glsl_type_singleton_decref();
 }
diff --git a/src/compiler/nir/tests/serialize_tests.cpp b/src/compiler/nir/tests/serialize_tests.cpp
index 327e5ec61d0..60e338e5791 100644
--- a/src/compiler/nir/tests/serialize_tests.cpp
+++ b/src/compiler/nir/tests/serialize_tests.cpp
@@ -38,8 +38,7 @@ protected:
    nir_alu_instr *get_last_alu(nir_shader *);
    void ASSERT_SWIZZLE_EQ(nir_alu_instr *, nir_alu_instr *, unsigned count, unsigned src);
 
-   void *mem_ctx;
-   nir_builder *b;
+   nir_builder *b, _b;
    nir_shader *dup;
    const nir_shader_compiler_options options;
 };
@@ -49,10 +48,8 @@ nir_serialize_test::nir_serialize_test()
 {
    glsl_type_singleton_init_or_ref();
 
-   mem_ctx = ralloc_context(NULL);
-
-   b = rzalloc(mem_ctx, nir_builder);
-   *b = nir_builder_init_simple_shader(mem_ctx, MESA_SHADER_COMPUTE, &options);
+   _b = nir_builder_init_simple_shader(NULL, MESA_SHADER_COMPUTE, &options);
+   b = &_b;
 }
 
 nir_serialize_test::~nir_serialize_test()
@@ -65,7 +62,7 @@ nir_serialize_test::~nir_serialize_test()
       nir_print_shader(dup, stdout);
    }
 
-   ralloc_free(mem_ctx);
+   ralloc_free(b->shader);
 
    glsl_type_singleton_decref();
 }
@@ -79,7 +76,7 @@ nir_serialize_test::serialize() {
 
    nir_serialize(&blob, b->shader, false);
    blob_reader_init(&reader, blob.data, blob.size);
-   nir_shader *cloned = nir_deserialize(mem_ctx, &options, &reader);
+   nir_shader *cloned = nir_deserialize(b->shader, &options, &reader);
    blob_finish(&blob);
 
    dup = cloned;
diff --git a/src/compiler/nir/tests/vars_tests.cpp b/src/compiler/nir/tests/vars_tests.cpp
index 1580b5dc493..63a99773df3 100644
--- a/src/compiler/nir/tests/vars_tests.cpp
+++ b/src/compiler/nir/tests/vars_tests.cpp
@@ -92,21 +92,19 @@ protected:
 
    nir_deref_instr *get_deref(nir_deref_type deref_type,
                               unsigned index);
-   void *mem_ctx;
    void *lin_ctx;
 
-   nir_builder *b;
+   nir_builder *b, _b;
 };
 
 nir_vars_test::nir_vars_test()
 {
    glsl_type_singleton_init_or_ref();
 
-   mem_ctx = ralloc_context(NULL);
-   lin_ctx = linear_alloc_parent(mem_ctx, 0);
    static const nir_shader_compiler_options options = { };
-   b = rzalloc(mem_ctx, nir_builder);
-   *b = nir_builder_init_simple_shader(mem_ctx, MESA_SHADER_COMPUTE, &options);
+   _b = nir_builder_init_simple_shader(NULL, MESA_SHADER_COMPUTE, &options);
+   b = &_b;
+   lin_ctx = linear_alloc_parent(b->shader, 0);
 }
 
 nir_vars_test::~nir_vars_test()
@@ -116,7 +114,7 @@ nir_vars_test::~nir_vars_test()
       nir_print_shader(b->shader, stdout);
    }
 
-   ralloc_free(mem_ctx);
+   ralloc_free(b->shader);
 
    glsl_type_singleton_decref();
 }
@@ -1840,7 +1838,7 @@ TEST_F(nir_split_vars_test, simple_no_split_array_struct)
    struct glsl_struct_field field;
 
    field.type = glsl_float_type();
-   field.name = ralloc_asprintf(b, "field1");
+   field.name = ralloc_asprintf(b->shader, "field1");
    field.location = -1;
    field.offset = 0;