Merge "Only set -Wall once."
diff --git a/cc/cc_test.go b/cc/cc_test.go
index 2951b5a..fb24624 100644
--- a/cc/cc_test.go
+++ b/cc/cc_test.go
@@ -4041,7 +4041,7 @@
 	conly := []string{"-fPIC", "${config.CommonGlobalConlyflags}"}
 	cppOnly := []string{"-fPIC", "${config.CommonGlobalCppflags}", "${config.DeviceGlobalCppflags}", "${config.ArmCppflags}"}
 
-	cflags := []string{"-Wall", "-Werror", "-std=candcpp"}
+	cflags := []string{"-Werror", "-std=candcpp"}
 	cstd := []string{"-std=gnu11", "-std=conly"}
 	cppstd := []string{"-std=gnu++17", "-std=cpp", "-fno-rtti"}
 
diff --git a/cc/compiler.go b/cc/compiler.go
index eb5458f..49b6fba 100644
--- a/cc/compiler.go
+++ b/cc/compiler.go
@@ -590,9 +590,8 @@
 		} else if !inList("-Werror", flags.Local.CFlags) && !inList("-Werror", flags.Local.CppFlags) {
 			if warningsAreAllowed(ctx.ModuleDir()) {
 				addToModuleList(ctx, modulesAddedWallKey, module)
-				flags.Local.CFlags = append([]string{"-Wall"}, flags.Local.CFlags...)
 			} else {
-				flags.Local.CFlags = append([]string{"-Wall", "-Werror"}, flags.Local.CFlags...)
+				flags.Local.CFlags = append([]string{"-Werror"}, flags.Local.CFlags...)
 			}
 		}
 	}