diff --git a/builder/picolibc.go b/builder/picolibc.go
index d3a095d6..436c3481 100644
--- a/builder/picolibc.go
+++ b/builder/picolibc.go
@@ -12,7 +12,7 @@ var Picolibc = Library{
 	name: "picolibc",
 	cflags: func() []string {
 		picolibcDir := filepath.Join(goenv.Get("TINYGOROOT"), "lib/picolibc/newlib/libc")
-		return []string{"-Werror", "-Wall", "-std=gnu11", "-D_COMPILING_NEWLIB", "--sysroot=" + picolibcDir, "-I" + picolibcDir + "/tinystdio", "-I" + goenv.Get("TINYGOROOT") + "/lib/picolibc-include"}
+		return []string{"-Werror", "-Wall", "-std=gnu11", "-D_COMPILING_NEWLIB", "-nostdlibinc", "-Xclang", "-internal-isystem", "-Xclang", picolibcDir + "/include", "-I" + picolibcDir + "/tinystdio", "-I" + goenv.Get("TINYGOROOT") + "/lib/picolibc-include"}
 	},
 	sourceDir: "lib/picolibc/newlib/libc",
 	sources: func(target string) []string {
diff --git a/compileopts/config.go b/compileopts/config.go
index 9ec71bf8..435dda80 100644
--- a/compileopts/config.go
+++ b/compileopts/config.go
@@ -173,7 +173,7 @@ func (c *Config) CFlags() []string {
 	}
 	if c.Target.Libc == "picolibc" {
 		root := goenv.Get("TINYGOROOT")
-		cflags = append(cflags, "--sysroot="+filepath.Join(root, "lib", "picolibc", "newlib", "libc"))
+		cflags = append(cflags, "-nostdlibinc", "-Xclang", "-internal-isystem", "-Xclang", filepath.Join(root, "lib", "picolibc", "newlib", "libc", "include"))
 		cflags = append(cflags, "-I"+filepath.Join(root, "lib/picolibc-include"))
 	}
 	return cflags