diff --git a/meta/classes/create-spdx-image-3.0.bbclass b/meta/classes-recipe/create-spdx-image-3.0.bbclass
similarity index 53%
rename from meta/classes/create-spdx-image-3.0.bbclass
rename to meta/classes-recipe/create-spdx-image-3.0.bbclass
index 1cad8537d1..fcae134d66 100644
--- a/meta/classes/create-spdx-image-3.0.bbclass
+++ b/meta/classes-recipe/create-spdx-image-3.0.bbclass
@@ -77,69 +77,3 @@ python do_create_image_sbom_spdx_setscene() {
     sstate_setscene(d)
 }
 addtask do_create_image_sbom_spdx_setscene
-
-do_populate_sdk[recrdeptask] += "do_create_spdx do_create_package_spdx"
-do_populate_sdk[cleandirs] += "${SPDXSDKWORK}"
-do_populate_sdk[postfuncs] += "sdk_create_sbom"
-POPULATE_SDK_POST_HOST_COMMAND:append:task-populate-sdk = " sdk_host_create_spdx"
-POPULATE_SDK_POST_TARGET_COMMAND:append:task-populate-sdk = " sdk_target_create_spdx"
-
-do_populate_sdk_ext[recrdeptask] += "do_create_spdx do_create_package_spdx"
-do_populate_sdk_ext[cleandirs] += "${SPDXSDKEXTWORK}"
-do_populate_sdk_ext[postfuncs] += "sdk_ext_create_sbom"
-POPULATE_SDK_POST_HOST_COMMAND:append:task-populate-sdk-ext = " sdk_ext_host_create_spdx"
-POPULATE_SDK_POST_TARGET_COMMAND:append:task-populate-sdk-ext = " sdk_ext_target_create_spdx"
-
-python sdk_host_create_spdx() {
-    from pathlib import Path
-    import oe.spdx30_tasks
-    spdx_work_dir = Path(d.getVar('SPDXSDKWORK'))
-
-    oe.spdx30_tasks.sdk_create_spdx(d, "host", spdx_work_dir, d.getVar("TOOLCHAIN_OUTPUTNAME"))
-}
-
-python sdk_target_create_spdx() {
-    from pathlib import Path
-    import oe.spdx30_tasks
-    spdx_work_dir = Path(d.getVar('SPDXSDKWORK'))
-
-    oe.spdx30_tasks.sdk_create_spdx(d, "target", spdx_work_dir, d.getVar("TOOLCHAIN_OUTPUTNAME"))
-}
-
-python sdk_ext_host_create_spdx() {
-    from pathlib import Path
-    import oe.spdx30_tasks
-    spdx_work_dir = Path(d.getVar('SPDXSDKEXTWORK'))
-
-    # TODO: This doesn't seem to work
-    oe.spdx30_tasks.sdk_create_spdx(d, "host", spdx_work_dir, d.getVar("TOOLCHAINEXT_OUTPUTNAME"))
-}
-
-python sdk_ext_target_create_spdx() {
-    from pathlib import Path
-    import oe.spdx30_tasks
-    spdx_work_dir = Path(d.getVar('SPDXSDKEXTWORK'))
-
-    # TODO: This doesn't seem to work
-    oe.spdx30_tasks.sdk_create_spdx(d, "target", spdx_work_dir, d.getVar("TOOLCHAINEXT_OUTPUTNAME"))
-}
-
-
-python sdk_create_sbom() {
-    from pathlib import Path
-    import oe.spdx30_tasks
-    sdk_deploydir = Path(d.getVar("SDKDEPLOYDIR"))
-    spdx_work_dir = Path(d.getVar('SPDXSDKWORK'))
-
-    oe.spdx30_tasks.create_sdk_sbom(d, sdk_deploydir, spdx_work_dir, d.getVar("TOOLCHAIN_OUTPUTNAME"))
-}
-
-python sdk_ext_create_sbom() {
-    from pathlib import Path
-    import oe.spdx30_tasks
-    sdk_deploydir = Path(d.getVar("SDKEXTDEPLOYDIR"))
-    spdx_work_dir = Path(d.getVar('SPDXSDKEXTWORK'))
-
-    oe.spdx30_tasks.create_sdk_sbom(d, sdk_deploydir, spdx_work_dir, d.getVar("TOOLCHAINEXT_OUTPUTNAME"))
-}
-
diff --git a/meta/classes-recipe/create-spdx-sdk-3.0.bbclass b/meta/classes-recipe/create-spdx-sdk-3.0.bbclass
new file mode 100644
index 0000000000..ea01a21cc5
--- /dev/null
+++ b/meta/classes-recipe/create-spdx-sdk-3.0.bbclass
@@ -0,0 +1,72 @@
+#
+# Copyright OpenEmbedded Contributors
+#
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# SPDX SDK tasks
+
+do_populate_sdk[recrdeptask] += "do_create_spdx do_create_package_spdx"
+do_populate_sdk[cleandirs] += "${SPDXSDKWORK}"
+do_populate_sdk[postfuncs] += "sdk_create_sbom"
+POPULATE_SDK_POST_HOST_COMMAND:append:task-populate-sdk = " sdk_host_create_spdx"
+POPULATE_SDK_POST_TARGET_COMMAND:append:task-populate-sdk = " sdk_target_create_spdx"
+
+do_populate_sdk_ext[recrdeptask] += "do_create_spdx do_create_package_spdx"
+do_populate_sdk_ext[cleandirs] += "${SPDXSDKEXTWORK}"
+do_populate_sdk_ext[postfuncs] += "sdk_ext_create_sbom"
+POPULATE_SDK_POST_HOST_COMMAND:append:task-populate-sdk-ext = " sdk_ext_host_create_spdx"
+POPULATE_SDK_POST_TARGET_COMMAND:append:task-populate-sdk-ext = " sdk_ext_target_create_spdx"
+
+python sdk_host_create_spdx() {
+    from pathlib import Path
+    import oe.spdx30_tasks
+    spdx_work_dir = Path(d.getVar('SPDXSDKWORK'))
+
+    oe.spdx30_tasks.sdk_create_spdx(d, "host", spdx_work_dir, d.getVar("TOOLCHAIN_OUTPUTNAME"))
+}
+
+python sdk_target_create_spdx() {
+    from pathlib import Path
+    import oe.spdx30_tasks
+    spdx_work_dir = Path(d.getVar('SPDXSDKWORK'))
+
+    oe.spdx30_tasks.sdk_create_spdx(d, "target", spdx_work_dir, d.getVar("TOOLCHAIN_OUTPUTNAME"))
+}
+
+python sdk_ext_host_create_spdx() {
+    from pathlib import Path
+    import oe.spdx30_tasks
+    spdx_work_dir = Path(d.getVar('SPDXSDKEXTWORK'))
+
+    # TODO: This doesn't seem to work
+    oe.spdx30_tasks.sdk_create_spdx(d, "host", spdx_work_dir, d.getVar("TOOLCHAINEXT_OUTPUTNAME"))
+}
+
+python sdk_ext_target_create_spdx() {
+    from pathlib import Path
+    import oe.spdx30_tasks
+    spdx_work_dir = Path(d.getVar('SPDXSDKEXTWORK'))
+
+    # TODO: This doesn't seem to work
+    oe.spdx30_tasks.sdk_create_spdx(d, "target", spdx_work_dir, d.getVar("TOOLCHAINEXT_OUTPUTNAME"))
+}
+
+
+python sdk_create_sbom() {
+    from pathlib import Path
+    import oe.spdx30_tasks
+    sdk_deploydir = Path(d.getVar("SDKDEPLOYDIR"))
+    spdx_work_dir = Path(d.getVar('SPDXSDKWORK'))
+
+    oe.spdx30_tasks.create_sdk_sbom(d, sdk_deploydir, spdx_work_dir, d.getVar("TOOLCHAIN_OUTPUTNAME"))
+}
+
+python sdk_ext_create_sbom() {
+    from pathlib import Path
+    import oe.spdx30_tasks
+    sdk_deploydir = Path(d.getVar("SDKEXTDEPLOYDIR"))
+    spdx_work_dir = Path(d.getVar('SPDXSDKEXTWORK'))
+
+    oe.spdx30_tasks.create_sdk_sbom(d, sdk_deploydir, spdx_work_dir, d.getVar("TOOLCHAINEXT_OUTPUTNAME"))
+}
+
diff --git a/meta/classes-recipe/populate_sdk_base.bbclass b/meta/classes-recipe/populate_sdk_base.bbclass
index 61a8b5e300..50bb81cd04 100644
--- a/meta/classes-recipe/populate_sdk_base.bbclass
+++ b/meta/classes-recipe/populate_sdk_base.bbclass
@@ -4,6 +4,9 @@
 # SPDX-License-Identifier: MIT
 #
 
+SDK_CLASSES += "${@bb.utils.contains("IMAGE_CLASSES", "testimage", "testsdk", "", d)}"
+inherit_defer ${SDK_CLASSES}
+
 PACKAGES = ""
 
 # This exists as an optimization for SPDX processing to only run in image and
diff --git a/meta/classes-recipe/testimage.bbclass b/meta/classes-recipe/testimage.bbclass
index 531330f384..6d1e1a107a 100644
--- a/meta/classes-recipe/testimage.bbclass
+++ b/meta/classes-recipe/testimage.bbclass
@@ -483,5 +483,3 @@ python () {
     if oe.types.boolean(d.getVar("TESTIMAGE_AUTO") or "False"):
         bb.build.addtask("testimage", "do_build", "do_image_complete", d)
 }
-
-inherit testsdk
diff --git a/meta/classes/create-spdx-3.0.bbclass b/meta/classes/create-spdx-3.0.bbclass
index 2eb44ba808..c1241e5856 100644
--- a/meta/classes/create-spdx-3.0.bbclass
+++ b/meta/classes/create-spdx-3.0.bbclass
@@ -115,6 +115,7 @@ SPDX_PACKAGE_SUPPLIER[doc] = "The base variable name to describe the Agent who \
 
 
 IMAGE_CLASSES:append = " create-spdx-image-3.0"
+SDK_CLASSES += "create-spdx-sdk-3.0"
 
 oe.spdx30_tasks.set_timestamp_now[vardepsexclude] = "SPDX_INCLUDE_TIMESTAMPS"
 oe.spdx30_tasks.get_package_sources_from_debug[vardepsexclude] += "STAGING_KERNEL_DIR"
diff --git a/meta/recipes-core/meta/buildtools-tarball.bb b/meta/recipes-core/meta/buildtools-tarball.bb
index 92fbda335d..e2ce5b3ecf 100644
--- a/meta/recipes-core/meta/buildtools-tarball.bb
+++ b/meta/recipes-core/meta/buildtools-tarball.bb
@@ -112,6 +112,9 @@ INHIBIT_DEFAULT_DEPS = "1"
 # Directory in testsdk that contains testcases
 TESTSDK_CASES = "buildtools-cases"
 
+# We have our own code, avoid deferred inherit
+SDK_CLASSES:remove = "testsdk"
+
 python do_testsdk() {
     import oeqa.sdk.testsdk
     testsdk = oeqa.sdk.testsdk.TestSDK()