diff --git a/src/cmd/go/alldocs.go b/src/cmd/go/alldocs.go
index 3febe880cdd..27f993aeb35 100644
--- a/src/cmd/go/alldocs.go
+++ b/src/cmd/go/alldocs.go
@@ -1887,6 +1887,9 @@
 // 	GOMIPS64
 // 		For GOARCH=mips64{,le}, whether to use floating point instructions.
 // 		Valid values are hardfloat (default), softfloat.
+// 	GOPPC64
+// 		For GOARCH=ppc64{,le}, the target ISA (Instruction Set Architecture).
+// 		Valid values are power8 (default), power9.
 // 	GOWASM
 // 		For GOARCH=wasm, comma-separated list of experimental WebAssembly features to use.
 // 		Valid values are satconv, signext.
diff --git a/src/cmd/go/internal/help/helpdoc.go b/src/cmd/go/internal/help/helpdoc.go
index 9ec65018926..b552777e3e0 100644
--- a/src/cmd/go/internal/help/helpdoc.go
+++ b/src/cmd/go/internal/help/helpdoc.go
@@ -598,6 +598,9 @@ Architecture-specific environment variables:
 	GOMIPS64
 		For GOARCH=mips64{,le}, whether to use floating point instructions.
 		Valid values are hardfloat (default), softfloat.
+	GOPPC64
+		For GOARCH=ppc64{,le}, the target ISA (Instruction Set Architecture).
+		Valid values are power8 (default), power9.
 	GOWASM
 		For GOARCH=wasm, comma-separated list of experimental WebAssembly features to use.
 		Valid values are satconv, signext.