diff --git a/platform-support.md b/platform-support.md
index 9de84ce5f..a62ccaac0 100644
--- a/platform-support.md
+++ b/platform-support.md
@@ -83,6 +83,10 @@ these platforms are required to have each of the following:
 | `powerpc-unknown-linux-gnu`       |  ✓  |  ✓  |  ✓  | PowerPC Linux                       |
 | `powerpc64-unknown-linux-gnu`     |  ✓  |  ✓  |  ✓  | PPC64 Linux                         |
 | `powerpc64le-unknown-linux-gnu`   |  ✓  |  ✓  |  ✓  | PPC64LE Linux                       |
+| `riscv32imac-unknown-none-elf`    |  *  |     |     | Bare RISC-V (RV32IMAC ISA)          |
+| `riscv32imc-unknown-none-elf`     |  *  |     |     | Bare RISC-V (RV32IMC ISA)           |
+| `riscv64gc-unknown-none-elf`      |  *  |     |     | Bare RISC-V (RV64IMAFDC ISA)        |
+| `riscv64imac-unknown-none-elf`    |  *  |     |     | Bare RISC-V (RV64IMAC ISA)          |
 | `s390x-unknown-linux-gnu`         |  ✓  |  ✓  |  ✓  | S390x Linux                         |
 | `sparc64-unknown-linux-gnu`       |  ✓  |     |     | SPARC Linux                         |
 | `sparcv9-sun-solaris`             |  ✓  |     |     | SPARC Solaris 10/11, illumos        |
@@ -103,6 +107,9 @@ these platforms are required to have each of the following:
 
 [Fortanix ABI]: https://edp.fortanix.com
 
+<em>*</em> These are bare-metal microcontroller targets that only have access to
+the core library, not std.
+
 ## Tier 2.5
 
 Tier 2.5 platforms can be thought of as "guaranteed to build", but without