diff --git a/tools/cmakev2/compat.cmake b/tools/cmakev2/compat.cmake
index cfac2f8bdc6..aad749ca9cb 100644
--- a/tools/cmakev2/compat.cmake
+++ b/tools/cmakev2/compat.cmake
@@ -702,8 +702,30 @@ function(idf_component_register)
     # Embedded files are managed in the idf_component_include function.
     idf_component_set_property("${COMPONENT_NAME}" EMBED_FILES "${ARG_EMBED_FILES}")
     idf_component_set_property("${COMPONENT_NAME}" EMBED_TXTFILES "${ARG_EMBED_TXTFILES}")
-    idf_component_set_property("${COMPONENT_NAME}" REQUIRES "${ARG_REQUIRES}")
-    idf_component_set_property("${COMPONENT_NAME}" PRIV_REQUIRES "${ARG_PRIV_REQUIRES}")
+    # The component manager's dependency injection runs before this component's
+    # CMakeLists.txt is evaluated (see idf_component_include() in
+    # component.cmake), and writes the manifest-derived names into both the
+    # MANAGED_* properties and the regular REQUIRES / PRIV_REQUIRES properties.
+    # The latter must not be overwritten by the component's own register call,
+    # else the manifest-derived transitive deps disappear from the build. Union
+    # the two so the persisted property is what the component author wrote
+    # PLUS what the manifest contributed.
+    idf_component_get_property(__existing_requires "${COMPONENT_NAME}" REQUIRES)
+    idf_component_get_property(__existing_priv_requires "${COMPONENT_NAME}" PRIV_REQUIRES)
+    set(__merged_requires "${ARG_REQUIRES}")
+    set(__merged_priv_requires "${ARG_PRIV_REQUIRES}")
+    foreach(__r IN LISTS __existing_requires)
+        if(__r AND NOT __r IN_LIST __merged_requires)
+            list(APPEND __merged_requires "${__r}")
+        endif()
+    endforeach()
+    foreach(__r IN LISTS __existing_priv_requires)
+        if(__r AND NOT __r IN_LIST __merged_priv_requires)
+            list(APPEND __merged_priv_requires "${__r}")
+        endif()
+    endforeach()
+    idf_component_set_property("${COMPONENT_NAME}" REQUIRES "${__merged_requires}")
+    idf_component_set_property("${COMPONENT_NAME}" PRIV_REQUIRES "${__merged_priv_requires}")
     idf_component_set_property("${COMPONENT_NAME}" REQUIRED_IDF_TARGETS "${ARG_REQUIRED_IDF_TARGETS}")
     idf_component_set_property("${COMPONENT_NAME}" COMPONENT_TYPE "${component_type}")
 endfunction()
diff --git a/tools/cmakev2/component.cmake b/tools/cmakev2/component.cmake
index cde6f103d8f..021dd9d357c 100644
--- a/tools/cmakev2/component.cmake
+++ b/tools/cmakev2/component.cmake
@@ -925,6 +925,29 @@ function(idf_component_include name)
     endif()
 
     list(APPEND __DEPENDENCY_CHAIN "${component_interface}")
+
+    # Inject managed dependencies BEFORE add_subdirectory() evaluates the
+    # component's CMakeLists.txt — otherwise any component that queries a
+    # managed dependency at register time via
+    # idf_component_get_property(... COMPONENT_LIB) finds nothing because the
+    # target hasn't been created yet.
+    idf_build_get_property(idf_component_manager IDF_COMPONENT_MANAGER)
+    if(idf_component_manager EQUAL 1)
+        idf_component_get_property(_comp_dir "${component_name}" COMPONENT_DIR)
+        if(EXISTS "${_comp_dir}/idf_component.yml")
+            __inject_requirements_for_component_from_manager("${component_name}")
+
+            idf_component_get_property(_managed_req "${component_name}" MANAGED_REQUIRES)
+            idf_component_get_property(_managed_priv_req "${component_name}" MANAGED_PRIV_REQUIRES)
+
+            foreach(_dep IN LISTS _managed_req _managed_priv_req)
+                if(_dep)
+                    idf_component_include("${_dep}")
+                endif()
+            endforeach()
+        endif()
+    endif()
+
     # Evaluate the CMakeLists.txt file of the component.
     idf_component_get_property(component_build_dir "${component_name}" COMPONENT_BUILD_DIR)
     add_subdirectory("${component_directory}" "${component_build_dir}")
@@ -1011,25 +1034,16 @@ function(idf_component_include name)
         target_add_binary_data(${COMPONENT_TARGET} "${file}" "TEXT")
     endforeach()
 
-    # Inject managed dependencies if component manager is enabled
+    # Link managed dependencies for cmakev1 components (backward compat).
+    # The injection and inclusion already happened before add_subdirectory().
     idf_build_get_property(idf_component_manager IDF_COMPONENT_MANAGER)
     idf_component_get_property(component_format "${component_name}" COMPONENT_FORMAT)
     if(idf_component_manager EQUAL 1)
         idf_component_get_property(component_dir "${component_name}" COMPONENT_DIR)
-        # Check if component has manifest for managed dependency injection
         if(EXISTS "${component_dir}/idf_component.yml")
-            __inject_requirements_for_component_from_manager("${component_name}")
-
-            # Include any managed dependencies
             idf_component_get_property(managed_requires "${component_name}" MANAGED_REQUIRES)
             idf_component_get_property(managed_priv_requires "${component_name}" MANAGED_PRIV_REQUIRES)
 
-            foreach(dep IN LISTS managed_requires managed_priv_requires)
-                if(dep)
-                    idf_component_include("${dep}")
-                endif()
-            endforeach()
-
             # For cmakev1 components, automatically link managed dependencies to maintain
             # backward compatibility.
             if("${component_format}" STREQUAL "CMAKEV1")