diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainVariables.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainVariables.java
index 5d2520b12ce0b3..8d333acd723061 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainVariables.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainVariables.java
@@ -29,6 +29,7 @@
 import com.google.devtools.build.lib.actions.Artifact;
 import com.google.devtools.build.lib.actions.InputMetadataProvider;
 import com.google.devtools.build.lib.actions.PathMapper;
+import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.collect.nestedset.Depset;
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 import com.google.devtools.build.lib.concurrent.BlazeInterners;
@@ -828,6 +829,7 @@ private static VariableValue asVariableValue(Object o) {
       case NoneType ignored -> null; // null has the same behavior as omitted field
       case Boolean b -> BooleanValue.of(b);
       case String s -> new StringValue(s);
+      case Label label -> new StringValue(label.expandToCommandLine());
       case Artifact artifact -> new ArtifactValue(artifact);
       case PathFragment pathFragment -> new PathFragmentValue(pathFragment);
       case Iterable<?> iterable -> new Sequence(ImmutableList.copyOf(iterable));