diff --git a/CMakeLists.txt b/CMakeLists.txt
index c87bc17b38c..3eee64ec288 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -104,6 +104,12 @@ if(CMAKE_C_COMPILER_ID MATCHES "GNU")
     list(APPEND c_compile_options "-Wno-old-style-declaration")
 endif()
 
+# TODO IDF-15784: remove in IDF v7.0 ?
+check_c_compiler_flag("-Wunused-but-set-variable=1" compiler_supports_wunused_but_set_variable_eq_1)
+if(compiler_supports_wunused_but_set_variable_eq_1)
+    list(APPEND compile_options "-Wunused-but-set-variable=1")
+endif()
+
 # Clang finds some warnings in IDF code which GCC doesn't.
 # All these warnings should be fixed before Clang is presented
 # as a toolchain choice for users.
diff --git a/tools/ci/configure_ci_environment.sh b/tools/ci/configure_ci_environment.sh
index 54f2e03159f..38f093cbe03 100644
--- a/tools/ci/configure_ci_environment.sh
+++ b/tools/ci/configure_ci_environment.sh
@@ -17,8 +17,17 @@ DEBUG_SHELL=${DEBUG_SHELL:-"0"}
 # (Depends on default options '-Wno-error=XXX' used in the IDF build system)
 
 if [ "$IDF_TOOLCHAIN" != "clang" ]; then
-    PEDANTIC_FLAGS="-Werror -Werror=deprecated-declarations -Werror=unused-variable -Werror=unused-but-set-variable -Werror=unused-function"
+    PEDANTIC_FLAGS="-Werror -Werror=deprecated-declarations -Werror=unused-variable -Werror=unused-function"
     export PEDANTIC_CFLAGS="${PEDANTIC_FLAGS} -Wstrict-prototypes"
+    # TODO IDF-15784
+    case "$CI_JOB_NAME" in
+        test_pytest_linux|test_sockets_on_host|test_transport_on_host|test_pytest_macos)
+        export PEDANTIC_CFLAGS="${PEDANTIC_CFLAGS} -Werror=unused-but-set-variable"
+        ;;
+    *)
+        export PEDANTIC_CFLAGS="${PEDANTIC_CFLAGS} -Werror=unused-but-set-variable=1"
+        ;;
+    esac
 else
     export PEDANTIC_CFLAGS="-Werror"
 fi
diff --git a/tools/cmakev2/project.cmake b/tools/cmakev2/project.cmake
index 22189e962aa..7aa49957a79 100644
--- a/tools/cmakev2/project.cmake
+++ b/tools/cmakev2/project.cmake
@@ -236,6 +236,12 @@ function(__init_project_configuration)
         list(APPEND c_compile_options "-Wno-old-style-declaration")
     endif()
 
+    # TODO IDF-15784: remove in IDF v7.0 ?
+    check_c_compiler_flag("-Wunused-but-set-variable=1" compiler_supports_wunused_but_set_variable_eq_1)
+    if(compiler_supports_wunused_but_set_variable_eq_1)
+        list(APPEND compile_options "-Wunused-but-set-variable=1")
+    endif()
+
     # Clang finds some warnings in IDF code which GCC doesn't.
     # All these warnings should be fixed before Clang is presented
     # as a toolchain choice for users.