diff --git a/tests/periph_cpuid/Makefile b/tests/periph_cpuid/Makefile
index 268f07cd86..dadc77f857 100644
--- a/tests/periph_cpuid/Makefile
+++ b/tests/periph_cpuid/Makefile
@@ -3,24 +3,3 @@ include ../Makefile.tests_common
 FEATURES_REQUIRED = periph_cpuid
 
 include $(RIOTBASE)/Makefile.include
-
-# Determine the CPUID_LEN based on the current architecture or CPU used in the
-# build system.
-ifneq (,$(filter arch_esp32,$(FEATURES_USED)))
-  CPUID_LEN = 7
-endif
-ifneq (,$(filter cc2538 efm32 ezr32wg nrf5%,$(CPU)))
-  CPUID_LEN = 8
-endif
-ifneq (,$(filter cc26x0 lpc1768 sam%,$(CPU)))
-  CPUID_LEN = 16
-endif
-ifneq (,$(filter fe310 kinetis stm32%,$(CPU)))
-  CPUID_LEN = 12
-endif
-
-# Use 4 as default as it is the minimum for all supported CPUs.
-CPUID_LEN ?= 4
-
-# Export CPUID_LEN env variable to the Python script.
-export CPUID_LEN
diff --git a/tests/periph_cpuid/main.c b/tests/periph_cpuid/main.c
index e6ad447714..b0d7806d54 100644
--- a/tests/periph_cpuid/main.c
+++ b/tests/periph_cpuid/main.c
@@ -32,6 +32,8 @@ int main(void)
     puts("Test for the CPUID driver");
     puts("This test is reading out the CPUID of the platforms CPU\n");
 
+    printf("CPUID_LEN: %u\n", CPUID_LEN);
+
     /* read the CPUID */
     cpuid_get(id);
 
diff --git a/tests/periph_cpuid/tests/01-run.py b/tests/periph_cpuid/tests/01-run.py
index 3deb058bf8..fd3dbcc57a 100755
--- a/tests/periph_cpuid/tests/01-run.py
+++ b/tests/periph_cpuid/tests/01-run.py
@@ -6,19 +6,17 @@
 # General Public License v2.1. See the file LICENSE in the top level
 # directory for more details.
 
-import os
 import sys
 from testrunner import run
 
 
-CPUID_LEN = int(os.getenv('CPUID_LEN') or 4)
-
-
 def testfunc(child):
     child.expect_exact('Test for the CPUID driver')
     child.expect_exact('This test is reading out the CPUID of the platforms CPU')
-    expected = 'CPUID:' + CPUID_LEN * r' 0x[0-9a-fA-F]{2}'
-    child.expect(expected)
+    child.expect(r'CPUID_LEN: (\d+)')
+    cpuid_len = int(child.match.group(1))
+    child.expect(r'CPUID:( 0x[0-9a-fA-F]{2})+\s*$')
+    assert child.match.group(0).count(' 0x') == cpuid_len
 
 
 if __name__ == "__main__":