diff --git a/BUILD.gn b/BUILD.gn
index 2011dea..724529c 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -102,7 +102,7 @@
 }
 
 _build_pigweed_default_at_all_optimization_levels("stm32f429i") {
-  toolchain_prefix = "$dir_pigweed/targets/stm32f429i-disc1:stm32f429i_disc1_"
+  toolchain_prefix = "$dir_pigweed/targets/stm32f429i_disc1:stm32f429i_disc1_"
 }
 
 if (pw_arduino_build_CORE_PATH != "") {
@@ -113,12 +113,12 @@
 
 _build_pigweed_default_at_all_optimization_levels("qemu_gcc") {
   toolchain_prefix =
-      "$dir_pigweed/targets/lm3s6965evb-qemu:lm3s6965evb_qemu_gcc_"
+      "$dir_pigweed/targets/lm3s6965evb_qemu:lm3s6965evb_qemu_gcc_"
 }
 
 _build_pigweed_default_at_all_optimization_levels("qemu_clang") {
   toolchain_prefix =
-      "$dir_pigweed/targets/lm3s6965evb-qemu:lm3s6965evb_qemu_clang_"
+      "$dir_pigweed/targets/lm3s6965evb_qemu:lm3s6965evb_qemu_clang_"
 }
 
 group("docs") {
diff --git a/docs/BUILD.gn b/docs/BUILD.gn
index 89c957f..1126bd4 100644
--- a/docs/BUILD.gn
+++ b/docs/BUILD.gn
@@ -48,8 +48,8 @@
     "$dir_pigweed/targets/arduino:target_docs",
     "$dir_pigweed/targets/docs:target_docs",
     "$dir_pigweed/targets/host:target_docs",
-    "$dir_pigweed/targets/lm3s6965evb-qemu:target_docs",
-    "$dir_pigweed/targets/stm32f429i-disc1:target_docs",
+    "$dir_pigweed/targets/lm3s6965evb_qemu:target_docs",
+    "$dir_pigweed/targets/stm32f429i_disc1:target_docs",
   ]
 }
 
diff --git a/pw_env_setup/BUILD.gn b/pw_env_setup/BUILD.gn
index caef4bf..b097e68 100644
--- a/pw_env_setup/BUILD.gn
+++ b/pw_env_setup/BUILD.gn
@@ -62,8 +62,8 @@
 # Python packages for supporting specific targets.
 pw_python_group("target_support_packages") {
   python_deps = [
-    "$dir_pigweed/targets/lm3s6965evb-qemu/py",
-    "$dir_pigweed/targets/stm32f429i-disc1/py",
+    "$dir_pigweed/targets/lm3s6965evb_qemu/py",
+    "$dir_pigweed/targets/stm32f429i_disc1/py",
   ]
 }
 
diff --git a/pw_hdlc/rpc_example/docs.rst b/pw_hdlc/rpc_example/docs.rst
index d4b4ca3..8021f0a 100644
--- a/pw_hdlc/rpc_example/docs.rst
+++ b/pw_hdlc/rpc_example/docs.rst
@@ -41,7 +41,7 @@
 
 .. code-block:: sh
 
- openocd -f targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/openocd_stm32f4xx.cfg \
+ openocd -f targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/openocd_stm32f4xx.cfg \
      -c "program out/stm32f429i_disc1_debug/obj/pw_hdlc/rpc_example/bin/rpc_example.elf"
 
 4. Invoke RPCs from in an interactive console
diff --git a/pw_target_runner/docs.rst b/pw_target_runner/docs.rst
index 28f20e9..25b210d 100644
--- a/pw_target_runner/docs.rst
+++ b/pw_target_runner/docs.rst
@@ -56,7 +56,7 @@
   runner {
     command: "stm32f429i_disc1_unit_test_runner"
     args: "--openocd-config"
-    args: "targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/openocd_stm32f4xx.cfg"
+    args: "targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/openocd_stm32f4xx.cfg"
     args: "--serial"
     args: "066DFF575051717867013127"
   }
@@ -64,7 +64,7 @@
   runner {
     command: "stm32f429i_disc1_unit_test_runner"
     args: "--openocd-config"
-    args: "targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/openocd_stm32f4xx.cfg"
+    args: "targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/openocd_stm32f4xx.cfg"
     args: "--serial"
     args: "0667FF494849887767196023"
   }
diff --git a/targets/docs/BUILD.gn b/targets/docs/BUILD.gn
index 73b1606..8f41247 100644
--- a/targets/docs/BUILD.gn
+++ b/targets/docs/BUILD.gn
@@ -14,7 +14,7 @@
 
 import("//build_overrides/pigweed.gni")
 
-import("$dir_pigweed/targets/stm32f429i-disc1/target_toolchains.gni")
+import("$dir_pigweed/targets/stm32f429i_disc1/target_toolchains.gni")
 import("$dir_pw_docgen/docs.gni")
 import("$dir_pw_protobuf_compiler/proto.gni")
 import("$dir_pw_third_party/nanopb/nanopb.gni")
diff --git a/targets/lm3s6965evb-qemu/BUILD b/targets/lm3s6965evb_qemu/BUILD
similarity index 100%
rename from targets/lm3s6965evb-qemu/BUILD
rename to targets/lm3s6965evb_qemu/BUILD
diff --git a/targets/lm3s6965evb-qemu/BUILD.gn b/targets/lm3s6965evb_qemu/BUILD.gn
similarity index 100%
rename from targets/lm3s6965evb-qemu/BUILD.gn
rename to targets/lm3s6965evb_qemu/BUILD.gn
diff --git a/targets/lm3s6965evb-qemu/boot.cc b/targets/lm3s6965evb_qemu/boot.cc
similarity index 100%
rename from targets/lm3s6965evb-qemu/boot.cc
rename to targets/lm3s6965evb_qemu/boot.cc
diff --git a/targets/lm3s6965evb-qemu/lm3s6965evb_executable.gni b/targets/lm3s6965evb_qemu/lm3s6965evb_executable.gni
similarity index 92%
rename from targets/lm3s6965evb-qemu/lm3s6965evb_executable.gni
rename to targets/lm3s6965evb_qemu/lm3s6965evb_executable.gni
index 70a87cb..bd54e8a 100644
--- a/targets/lm3s6965evb-qemu/lm3s6965evb_executable.gni
+++ b/targets/lm3s6965evb_qemu/lm3s6965evb_executable.gni
@@ -21,6 +21,6 @@
     if (!defined(deps)) {
       deps = []
     }
-    deps += [ "$dir_pigweed/targets/lm3s6965evb-qemu:pre_init" ]
+    deps += [ "$dir_pigweed/targets/lm3s6965evb_qemu:pre_init" ]
   }
 }
diff --git a/targets/lm3s6965evb-qemu/py/BUILD.gn b/targets/lm3s6965evb_qemu/py/BUILD.gn
similarity index 100%
rename from targets/lm3s6965evb-qemu/py/BUILD.gn
rename to targets/lm3s6965evb_qemu/py/BUILD.gn
diff --git a/targets/lm3s6965evb-qemu/py/lm3s6965evb_qemu_utils/__init__.py b/targets/lm3s6965evb_qemu/py/lm3s6965evb_qemu_utils/__init__.py
similarity index 100%
rename from targets/lm3s6965evb-qemu/py/lm3s6965evb_qemu_utils/__init__.py
rename to targets/lm3s6965evb_qemu/py/lm3s6965evb_qemu_utils/__init__.py
diff --git a/targets/lm3s6965evb-qemu/py/lm3s6965evb_qemu_utils/py.typed b/targets/lm3s6965evb_qemu/py/lm3s6965evb_qemu_utils/py.typed
similarity index 100%
rename from targets/lm3s6965evb-qemu/py/lm3s6965evb_qemu_utils/py.typed
rename to targets/lm3s6965evb_qemu/py/lm3s6965evb_qemu_utils/py.typed
diff --git a/targets/lm3s6965evb-qemu/py/lm3s6965evb_qemu_utils/unit_test_runner.py b/targets/lm3s6965evb_qemu/py/lm3s6965evb_qemu_utils/unit_test_runner.py
similarity index 100%
rename from targets/lm3s6965evb-qemu/py/lm3s6965evb_qemu_utils/unit_test_runner.py
rename to targets/lm3s6965evb_qemu/py/lm3s6965evb_qemu_utils/unit_test_runner.py
diff --git a/targets/lm3s6965evb-qemu/py/setup.py b/targets/lm3s6965evb_qemu/py/setup.py
similarity index 100%
rename from targets/lm3s6965evb-qemu/py/setup.py
rename to targets/lm3s6965evb_qemu/py/setup.py
diff --git a/targets/lm3s6965evb-qemu/target_docs.rst b/targets/lm3s6965evb_qemu/target_docs.rst
similarity index 100%
rename from targets/lm3s6965evb-qemu/target_docs.rst
rename to targets/lm3s6965evb_qemu/target_docs.rst
diff --git a/targets/lm3s6965evb-qemu/target_toolchains.gni b/targets/lm3s6965evb_qemu/target_toolchains.gni
similarity index 100%
rename from targets/lm3s6965evb-qemu/target_toolchains.gni
rename to targets/lm3s6965evb_qemu/target_toolchains.gni
diff --git a/targets/lm3s6965evb-qemu/vector_table.c b/targets/lm3s6965evb_qemu/vector_table.c
similarity index 100%
rename from targets/lm3s6965evb-qemu/vector_table.c
rename to targets/lm3s6965evb_qemu/vector_table.c
diff --git a/targets/stm32f429i-disc1/BUILD b/targets/stm32f429i_disc1/BUILD
similarity index 100%
rename from targets/stm32f429i-disc1/BUILD
rename to targets/stm32f429i_disc1/BUILD
diff --git a/targets/stm32f429i-disc1/BUILD.gn b/targets/stm32f429i_disc1/BUILD.gn
similarity index 100%
rename from targets/stm32f429i-disc1/BUILD.gn
rename to targets/stm32f429i_disc1/BUILD.gn
diff --git a/targets/stm32f429i-disc1/boot.cc b/targets/stm32f429i_disc1/boot.cc
similarity index 100%
rename from targets/stm32f429i-disc1/boot.cc
rename to targets/stm32f429i_disc1/boot.cc
diff --git a/targets/stm32f429i-disc1/py/BUILD.gn b/targets/stm32f429i_disc1/py/BUILD.gn
similarity index 100%
rename from targets/stm32f429i-disc1/py/BUILD.gn
rename to targets/stm32f429i_disc1/py/BUILD.gn
diff --git a/targets/stm32f429i-disc1/py/setup.py b/targets/stm32f429i_disc1/py/setup.py
similarity index 100%
rename from targets/stm32f429i-disc1/py/setup.py
rename to targets/stm32f429i_disc1/py/setup.py
diff --git a/targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/__init__.py b/targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/__init__.py
similarity index 100%
rename from targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/__init__.py
rename to targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/__init__.py
diff --git a/targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/openocd_stm32f4xx.cfg b/targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/openocd_stm32f4xx.cfg
similarity index 100%
rename from targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/openocd_stm32f4xx.cfg
rename to targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/openocd_stm32f4xx.cfg
diff --git a/targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/py.typed b/targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/py.typed
similarity index 100%
rename from targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/py.typed
rename to targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/py.typed
diff --git a/targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/stm32f429i_detector.py b/targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/stm32f429i_detector.py
similarity index 100%
rename from targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/stm32f429i_detector.py
rename to targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/stm32f429i_detector.py
diff --git a/targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/unit_test_client.py b/targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/unit_test_client.py
similarity index 100%
rename from targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/unit_test_client.py
rename to targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/unit_test_client.py
diff --git a/targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/unit_test_runner.py b/targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/unit_test_runner.py
similarity index 100%
rename from targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/unit_test_runner.py
rename to targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/unit_test_runner.py
diff --git a/targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/unit_test_server.py b/targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/unit_test_server.py
similarity index 100%
rename from targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/unit_test_server.py
rename to targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/unit_test_server.py
diff --git a/targets/stm32f429i-disc1/stm32f429i_executable.gni b/targets/stm32f429i_disc1/stm32f429i_executable.gni
similarity index 94%
rename from targets/stm32f429i-disc1/stm32f429i_executable.gni
rename to targets/stm32f429i_disc1/stm32f429i_executable.gni
index 99190cc..4dafe8a 100644
--- a/targets/stm32f429i-disc1/stm32f429i_executable.gni
+++ b/targets/stm32f429i_disc1/stm32f429i_executable.gni
@@ -22,7 +22,7 @@
     if (!defined(deps)) {
       deps = []
     }
-    deps += [ "$dir_pigweed/targets/stm32f429i-disc1:pre_init" ]
+    deps += [ "$dir_pigweed/targets/stm32f429i_disc1:pre_init" ]
     if (pw_malloc_BACKEND != "") {
       if (!defined(configs)) {
         configs = []
diff --git a/targets/stm32f429i-disc1/system_rpc_server.cc b/targets/stm32f429i_disc1/system_rpc_server.cc
similarity index 100%
rename from targets/stm32f429i-disc1/system_rpc_server.cc
rename to targets/stm32f429i_disc1/system_rpc_server.cc
diff --git a/targets/stm32f429i-disc1/target_docs.rst b/targets/stm32f429i_disc1/target_docs.rst
similarity index 98%
rename from targets/stm32f429i-disc1/target_docs.rst
rename to targets/stm32f429i_disc1/target_docs.rst
index 2e4fcbd..64b4c29 100644
--- a/targets/stm32f429i-disc1/target_docs.rst
+++ b/targets/stm32f429i_disc1/target_docs.rst
@@ -115,7 +115,7 @@
 
    .. code:: sh
 
-     $ openocd -f targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/openocd_stm32f4xx.cfg
+     $ openocd -f targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/openocd_stm32f4xx.cfg
 
 #. Connect GDB to the running OpenOCD instance in terminal B
 
@@ -143,7 +143,7 @@
 
 .. code:: sh
 
-  $ openocd -f targets/stm32f429i-disc1/py/stm32f429i_disc1_utils/openocd_stm32f4xx.cfg
+  $ openocd -f targets/stm32f429i_disc1/py/stm32f429i_disc1_utils/openocd_stm32f4xx.cfg
 
 Typical output:
 
diff --git a/targets/stm32f429i-disc1/target_toolchains.gni b/targets/stm32f429i_disc1/target_toolchains.gni
similarity index 98%
rename from targets/stm32f429i-disc1/target_toolchains.gni
rename to targets/stm32f429i_disc1/target_toolchains.gni
index 8117109..d20dba0 100644
--- a/targets/stm32f429i-disc1/target_toolchains.gni
+++ b/targets/stm32f429i_disc1/target_toolchains.gni
@@ -55,7 +55,7 @@
   pw_log_BACKEND = dir_pw_log_basic
   pw_sys_io_BACKEND = dir_pw_sys_io_baremetal_stm32f429
   pw_rpc_system_server_BACKEND =
-      "$dir_pigweed/targets/stm32f429i-disc1:system_rpc_server"
+      "$dir_pigweed/targets/stm32f429i_disc1:system_rpc_server"
   pw_malloc_BACKEND = dir_pw_malloc_freelist
 
   pw_boot_armv7m_LINK_CONFIG_DEFINES = [
diff --git a/targets/stm32f429i-disc1/vector_table.c b/targets/stm32f429i_disc1/vector_table.c
similarity index 100%
rename from targets/stm32f429i-disc1/vector_table.c
rename to targets/stm32f429i_disc1/vector_table.c