diff --git a/tests/pkg_micro-ecc-with-hwrng/tests/01-run.py b/tests/pkg_micro-ecc-with-hwrng/tests/01-run.py
index 86abe6d980..369786b01d 100755
--- a/tests/pkg_micro-ecc-with-hwrng/tests/01-run.py
+++ b/tests/pkg_micro-ecc-with-hwrng/tests/01-run.py
@@ -4,6 +4,11 @@ import sys
 from testrunner import run
 
 
+# Use a custom global timeout for slow hardware. On microbit (nrf51), the
+# test completes in 120s.
+TIMEOUT = 200
+
+
 def testfunc(child):
     child.expect_exact('micro-ecc compiled!')
     child.expect_exact('Testing 16 random private key pairs and signature '
@@ -13,4 +18,4 @@ def testfunc(child):
 
 
 if __name__ == "__main__":
-    sys.exit(run(testfunc, timeout=60))
+    sys.exit(run(testfunc, timeout=TIMEOUT))
diff --git a/tests/pkg_micro-ecc/tests/01-run.py b/tests/pkg_micro-ecc/tests/01-run.py
index 5eddfb3dcc..9f110e4495 100755
--- a/tests/pkg_micro-ecc/tests/01-run.py
+++ b/tests/pkg_micro-ecc/tests/01-run.py
@@ -4,6 +4,11 @@ import sys
 from testrunner import run
 
 
+# Use a custom global timeout for slow hardware. On microbit (nrf51), the
+# test completes in 80s.
+TIMEOUT = 100
+
+
 def testfunc(child):
     child.expect_exact('micro-ecc compiled!')
     child.expect_exact('Testing 16 random private key pairs and signature '
@@ -13,4 +18,4 @@ def testfunc(child):
 
 
 if __name__ == "__main__":
-    sys.exit(run(testfunc, timeout=60))
+    sys.exit(run(testfunc, timeout=TIMEOUT))