diff --git a/spec/build/bsps/bspopts.yml b/spec/build/bsps/bspopts.yml
index d43136e94e..4a4c06d321 100644
--- a/spec/build/bsps/bspopts.yml
+++ b/spec/build/bsps/bspopts.yml
@@ -7,6 +7,12 @@ guard: __BSP_OPTIONS_H
 include-headers: []
 install-path: ${BSP_INCLUDEDIR}
 links:
+- role: build-dependency
+  uid: optbspoptflags
+- role: build-dependency
+  uid: optcpukitoptflags
+- role: build-dependency
+  uid: opttestoptflags
 - role: build-dependency
   uid: optabi
 - role: build-dependency
@@ -17,6 +23,8 @@ links:
   uid: optfatalverb
 - role: build-dependency
   uid: optincludes
+- role: build-dependency
+  uid: optcflags
 - role: build-dependency
   uid: optlinkflags
 - role: build-dependency
diff --git a/spec/build/bsps/optbspoptflags.yml b/spec/build/bsps/optbspoptflags.yml
new file mode 100644
index 0000000000..40dbb6c7ab
--- /dev/null
+++ b/spec/build/bsps/optbspoptflags.yml
@@ -0,0 +1,18 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+actions:
+- get-string: null
+- substitute: null
+- split: null
+- env-assign: null
+build-type: option
+copyrights:
+- Copyright (C) 2022 embedded brains GmbH (http://www.embedded-brains.de)
+default: ${OPTIMIZATION_FLAGS}
+default-by-variant: []
+description: |
+  Optimization flags passed to C and C++ compilers for the BSP.
+enabled-by: true
+format: '{}'
+links: []
+name: BSP_OPTIMIZATION_FLAGS
+type: build
diff --git a/spec/build/bsps/optcflags.yml b/spec/build/bsps/optcflags.yml
new file mode 100644
index 0000000000..ef03940bff
--- /dev/null
+++ b/spec/build/bsps/optcflags.yml
@@ -0,0 +1,17 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+actions:
+- set-value: |
+    ${BSP_OPTIMIZATION_FLAGS}
+- substitute: null
+- split: null
+- env-assign: null
+build-type: option
+copyrights:
+- Copyright (C) 2022 embedded brains GmbH (http://www.embedded-brains.de)
+default: null
+default-by-variant: []
+description: ''
+enabled-by: true
+links: []
+name: BSP_CFLAGS
+type: build
diff --git a/spec/build/bsps/optcpukitoptflags.yml b/spec/build/bsps/optcpukitoptflags.yml
new file mode 100644
index 0000000000..3baec4b8c8
--- /dev/null
+++ b/spec/build/bsps/optcpukitoptflags.yml
@@ -0,0 +1,18 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+actions:
+- get-string: null
+- substitute: null
+- split: null
+- env-assign: null
+build-type: option
+copyrights:
+- Copyright (C) 2022 embedded brains GmbH (http://www.embedded-brains.de)
+default: ${OPTIMIZATION_FLAGS}
+default-by-variant: []
+description: |
+  Optimization flags passed to C and C++ compilers for the CPU kit.
+enabled-by: true
+format: '{}'
+links: []
+name: CPUKIT_OPTIMIZATION_FLAGS
+type: build
diff --git a/spec/build/bsps/opto0.yml b/spec/build/bsps/opto0.yml
index 406286980f..9f54709c07 100644
--- a/spec/build/bsps/opto0.yml
+++ b/spec/build/bsps/opto0.yml
@@ -3,8 +3,6 @@ actions:
 - get-string: null
 - split: null
 - env-assign: null
-- env-append: CFLAGS
-- env-append: CXXFLAGS
 build-type: option
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
@@ -15,7 +13,7 @@ default:
 - -ffunction-sections
 default-by-variant: []
 description: |
-  Optimization flags passed to the C and C++ compiler
+  Default optimization flags for C and C++ compilers.
 enabled-by: true
 links: []
 name: OPTIMIZATION_FLAGS
diff --git a/spec/build/bsps/opto1.yml b/spec/build/bsps/opto1.yml
index 52d285c2ab..e0668a887b 100644
--- a/spec/build/bsps/opto1.yml
+++ b/spec/build/bsps/opto1.yml
@@ -3,8 +3,6 @@ actions:
 - get-string: null
 - split: null
 - env-assign: null
-- env-append: CFLAGS
-- env-append: CXXFLAGS
 build-type: option
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
@@ -15,7 +13,7 @@ default:
 - -ffunction-sections
 default-by-variant: []
 description: |
-  Optimization flags passed to the C and C++ compiler
+  Default optimization flags for C and C++ compilers.
 enabled-by: true
 links: []
 name: OPTIMIZATION_FLAGS
diff --git a/spec/build/bsps/opto2.yml b/spec/build/bsps/opto2.yml
index 071e5411d5..7b54556c5b 100644
--- a/spec/build/bsps/opto2.yml
+++ b/spec/build/bsps/opto2.yml
@@ -3,8 +3,6 @@ actions:
 - get-string: null
 - split: null
 - env-assign: null
-- env-append: CFLAGS
-- env-append: CXXFLAGS
 build-type: option
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
@@ -15,7 +13,7 @@ default:
 - -ffunction-sections
 default-by-variant: []
 description: |
-  Optimization flags passed to the C and C++ compiler
+  Default optimization flags for C and C++ compilers.
 enabled-by: true
 links: []
 name: OPTIMIZATION_FLAGS
diff --git a/spec/build/bsps/optog.yml b/spec/build/bsps/optog.yml
index d08bd7b2b2..2eab2acdd1 100644
--- a/spec/build/bsps/optog.yml
+++ b/spec/build/bsps/optog.yml
@@ -3,8 +3,6 @@ actions:
 - get-string: null
 - split: null
 - env-assign: null
-- env-append: CFLAGS
-- env-append: CXXFLAGS
 build-type: option
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
@@ -15,7 +13,7 @@ default:
 - -ffunction-sections
 default-by-variant: []
 description: |
-  Optimization flags passed to the C and C++ compiler
+  Default optimization flags for C and C++ compilers.
 enabled-by: true
 links: []
 name: OPTIMIZATION_FLAGS
diff --git a/spec/build/bsps/optos.yml b/spec/build/bsps/optos.yml
index df9e0efd02..1c2c106064 100644
--- a/spec/build/bsps/optos.yml
+++ b/spec/build/bsps/optos.yml
@@ -3,8 +3,6 @@ actions:
 - get-string: null
 - split: null
 - env-assign: null
-- env-append: CFLAGS
-- env-append: CXXFLAGS
 build-type: option
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
@@ -15,7 +13,7 @@ default:
 - -ffunction-sections
 default-by-variant: []
 description: |
-  Optimization flags passed to the C and C++ compiler
+  Default optimization flags for C and C++ compilers.
 enabled-by: true
 links: []
 name: OPTIMIZATION_FLAGS
diff --git a/spec/build/bsps/opttestoptflags.yml b/spec/build/bsps/opttestoptflags.yml
new file mode 100644
index 0000000000..43e0c92c07
--- /dev/null
+++ b/spec/build/bsps/opttestoptflags.yml
@@ -0,0 +1,18 @@
+SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
+actions:
+- get-string: null
+- substitute: null
+- split: null
+- env-assign: null
+build-type: option
+copyrights:
+- Copyright (C) 2022 embedded brains GmbH (http://www.embedded-brains.de)
+default: ${OPTIMIZATION_FLAGS}
+default-by-variant: []
+description: |
+  Optimization flags passed to C and C++ compiler for tests.
+enabled-by: true
+format: '{}'
+links: []
+name: TEST_OPTIMIZATION_FLAGS
+type: build
diff --git a/spec/build/cpukit/grp.yml b/spec/build/cpukit/grp.yml
index 24aa2f0634..ec9cab2167 100644
--- a/spec/build/cpukit/grp.yml
+++ b/spec/build/cpukit/grp.yml
@@ -1,10 +1,12 @@
 SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
 build-type: group
-cflags: []
+cflags:
+- ${CPUKIT_OPTIMIZATION_FLAGS}
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
 cppflags: []
-cxxflags: []
+cxxflags:
+- ${CPUKIT_OPTIMIZATION_FLAGS}
 enabled-by: true
 includes: []
 install: []
diff --git a/spec/build/testsuites/grp.yml b/spec/build/testsuites/grp.yml
index 82c7b87f2e..18c8ccd4d8 100644
--- a/spec/build/testsuites/grp.yml
+++ b/spec/build/testsuites/grp.yml
@@ -1,10 +1,12 @@
 SPDX-License-Identifier: CC-BY-SA-4.0 OR BSD-2-Clause
 build-type: group
-cflags: []
+cflags:
+- ${TEST_OPTIMIZATION_FLAGS}
 copyrights:
 - Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
 cppflags: []
-cxxflags: []
+cxxflags:
+- ${TEST_OPTIMIZATION_FLAGS}
 enabled-by: true
 includes:
 - ${BSP_INCLUDES}
diff --git a/wscript b/wscript
index 9894dcd7fd..4071cc9ef8 100755
--- a/wscript
+++ b/wscript
@@ -625,7 +625,7 @@ class BSPItem(Item):
             + bld.env.BSP_INCLUDES
             + self.substitute(bld, self.data["includes"]),
             self.substitute(bld, self.data["cppflags"]),
-            self.substitute(bld, self.data["cflags"]),
+            bld.env.BSP_CFLAGS + self.substitute(bld, self.data["cflags"]),
             [],
             [],
             [],