diff --git a/compiler/compiler.go b/compiler/compiler.go
index 00e008fb..d82c00f2 100644
--- a/compiler/compiler.go
+++ b/compiler/compiler.go
@@ -169,7 +169,7 @@ func (c *Compiler) TargetData() llvm.TargetData {
 func (c *Compiler) selectGC() string {
 	gc := c.GC
 	if gc == "" {
-		gc = "dumb"
+		gc = "leaking"
 	}
 	return gc
 }
diff --git a/main.go b/main.go
index 99d021d3..ad5ede3e 100644
--- a/main.go
+++ b/main.go
@@ -585,7 +585,7 @@ func handleCompilerError(err error) {
 func main() {
 	outpath := flag.String("o", "", "output filename")
 	opt := flag.String("opt", "z", "optimization level: 0, 1, 2, s, z")
-	gc := flag.String("gc", "", "garbage collector to use (none, dumb, marksweep)")
+	gc := flag.String("gc", "", "garbage collector to use (none, leaking, conservative)")
 	panicStrategy := flag.String("panic", "print", "panic strategy (abort, trap)")
 	printIR := flag.Bool("printir", false, "print LLVM IR")
 	dumpSSA := flag.Bool("dumpssa", false, "dump internal Go SSA")
diff --git a/src/runtime/gc_marksweep.go b/src/runtime/gc_conservative.go
similarity index 99%
rename from src/runtime/gc_marksweep.go
rename to src/runtime/gc_conservative.go
index 45eab6bc..dd1e5211 100644
--- a/src/runtime/gc_marksweep.go
+++ b/src/runtime/gc_conservative.go
@@ -1,4 +1,4 @@
-// +build gc.marksweep
+// +build gc.conservative
 
 package runtime
 
diff --git a/src/runtime/gc_dumb.go b/src/runtime/gc_leaking.go
similarity index 98%
rename from src/runtime/gc_dumb.go
rename to src/runtime/gc_leaking.go
index 92527364..fb0f9086 100644
--- a/src/runtime/gc_dumb.go
+++ b/src/runtime/gc_leaking.go
@@ -1,4 +1,4 @@
-// +build gc.dumb
+// +build gc.leaking
 
 package runtime
 
diff --git a/targets/cortex-m.json b/targets/cortex-m.json
index a8e8f612..7fb1b028 100644
--- a/targets/cortex-m.json
+++ b/targets/cortex-m.json
@@ -3,7 +3,7 @@
 	"goos": "linux",
 	"goarch": "arm",
 	"compiler": "clang",
-	"gc": "marksweep",
+	"gc": "conservative",
 	"linker": "ld.lld",
 	"rtlib": "compiler-rt",
 	"cflags": [