diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -19,13 +19,13 @@
 set(REQUIRED_QT_VERSION 5.11.0)
 find_package(Qt5Core ${REQUIRED_QT_VERSION} REQUIRED NO_MODULE)
 
-
-include(GenerateExportHeader)
-
+include(ECMGenerateExportHeader)
 include(ECMSetupVersion)
 include(ECMGenerateHeaders)
 include(ECMAddQch)
 
+set(EXCLUDE_DEPRECATED_BEFORE_AND_AT 0 CACHE STRING "Control the range of deprecated API excluded from the build [default=0].")
+
 option(BUILD_QCH "Build API documentation in QCH format (for e.g. Qt Assistant, Qt Creator & KDevelop)" OFF)
 add_feature_info(QCH ${BUILD_QCH} "API documentation in QCH format (for e.g. Qt Assistant, Qt Creator & KDevelop)")
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -35,8 +35,15 @@
 )
 
 add_library(KF5ThreadWeaver ${ThreadWeaver_LIB_SRCS})
-generate_export_header(KF5ThreadWeaver BASE_NAME ThreadWeaver)
 add_library(KF5::ThreadWeaver ALIAS KF5ThreadWeaver)
+ecm_generate_export_header(KF5ThreadWeaver
+    BASE_NAME ThreadWeaver
+    # GROUP_BASE_NAME KF <- enable once all of KF modules use ecm_generate_export_header
+    VERSION ${KF5_VERSION}
+    DEPRECATED_BASE_VERSION 0
+    DEPRECATION_VERSIONS 5.0
+    EXCLUDE_DEPRECATED_BEFORE_AND_AT ${EXCLUDE_DEPRECATED_BEFORE_AND_AT}
+)
 target_link_libraries(KF5ThreadWeaver PUBLIC Qt5::Core)
 set(threadweaver_BUILD_INCLUDE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/.. ${CMAKE_CURRENT_BINARY_DIR})
 target_include_directories(KF5ThreadWeaver PUBLIC "$<BUILD_INTERFACE:${threadweaver_BUILD_INCLUDE_DIRS}>")
diff --git a/src/collection.h b/src/collection.h
--- a/src/collection.h
+++ b/src/collection.h
@@ -68,9 +68,11 @@
     /** Return the number of elements in the collection. */
     int elementCount() const;
 
-    //FIXME remove
-    /** @deprecated Use elementCount(). */
+#if THREADWEAVER_ENABLE_DEPRECATED_SINCE(5, 0)
+    /** @deprecated Since 5.0, use elementCount(). */
+    THREADWEAVER_DEPRECATED_VERSION(5, 0, "Use Collection::elementCount()")
     int jobListLength() const;
+#endif
 
     /** @brief Add the job to this collection by pointer. */
     Collection &operator<<(ThreadWeaver::JobInterface *job);
diff --git a/src/collection.cpp b/src/collection.cpp
--- a/src/collection.cpp
+++ b/src/collection.cpp
@@ -180,11 +180,13 @@
 }
 
 
+#if THREADWEAVER_BUILD_DEPRECATED_SINCE(5, 0)
 int Collection::jobListLength() const
 {
     QMutexLocker l(mutex()); Q_UNUSED(l);
     return jobListLength_locked();
 }
+#endif
 
 int Collection::jobListLength_locked() const
 {