diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 1c65e30f2f6..cb90e3998ae 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -59,6 +59,26 @@ see following paragraph):
 ```shell
 task test-integration
 ```
+### Running only some tests
+By default, all tests from all go packages are run. To run only unit
+tests from one or more specific packages, you can set the TARGETS
+environment variable, e.g.:
+
+    TARGETS=./arduino/cores/packagemanager task test-unit
+
+Alternatively, to run only some specific test(s), you can specify a regex
+to match against the test function name:
+
+    TEST_REGEX='^TestTryBuild.*' task test-unit
+
+Both can be combined as well, typically to run only a specific test:
+
+    TEST_REGEX='^TestFindBoardWithFQBN$' TARGETS=./arduino/cores/packagemanager task test-unit
+
+For integration test, the same options are supported. Note that when not
+specified, `TEST_REGEX` defaults to "Integration" to select only
+integration tests, so if you specify a broader regex, this could cause
+non-integration tests to be run as well.
 
 ### Integration tests
 
diff --git a/Taskfile.yml b/Taskfile.yml
index 86f4f2b218a..325172222d5 100755
--- a/Taskfile.yml
+++ b/Taskfile.yml
@@ -21,12 +21,12 @@ tasks:
   test-unit:
     desc: Run unit tests only
     cmds:
-      - go test -short {{ default "-v" .GOFLAGS }} -coverprofile=coverage_unit.txt {{ default .DEFAULT_TARGETS .TARGETS }} {{.TEST_LDFLAGS}}
+      - go test -short -run '{{ default ".*" .TEST_REGEX }}' {{ default "-v" .GOFLAGS }} -coverprofile=coverage_unit.txt {{ default .DEFAULT_TARGETS .TARGETS }} {{.TEST_LDFLAGS}}
 
   test-integration:
     desc: Run integration tests only
     cmds:
-      - go test -run Integration {{ default "-v" .GOFLAGS }} -coverprofile=coverage_integ.txt {{ default .DEFAULT_TARGETS .TARGETS }} {{.TEST_LDFLAGS}}
+      - go test -run '{{ default "Integration" .TEST_REGEX }}' {{ default "-v" .GOFLAGS }} -coverprofile=coverage_integ.txt {{ default .DEFAULT_TARGETS .TARGETS }} {{.TEST_LDFLAGS}}
       - pytest test
 
   test-legacy: