diff --git a/src/main/java/com/google/devtools/build/lib/remote/RemoteServerCapabilities.java b/src/main/java/com/google/devtools/build/lib/remote/RemoteServerCapabilities.java
index 0afb9894217f3c..4904cff546cd53 100644
--- a/src/main/java/com/google/devtools/build/lib/remote/RemoteServerCapabilities.java
+++ b/src/main/java/com/google/devtools/build/lib/remote/RemoteServerCapabilities.java
@@ -201,17 +201,23 @@ public static ClientServerCompatibilityStatus checkClientServerCompatibility(
         return result.build(); // No point checking other execution fields.
       }
 
-      // Check execution digest function.
-      if (execCap.getDigestFunction() == DigestFunction.Value.UNKNOWN) {
-        // Server side error -- this is not supposed to happen.
-        result.addError("Remote server error: UNKNOWN execution digest function.");
-      }
-      if (execCap.getDigestFunction() != digestFunction) {
+      // Check execution digest function. The protocol only later added
+      // support for multiple digest functions for remote execution, so
+      // check both the singular and repeated field.
+      if (execCap.getDigestFunctionsList().isEmpty() &&
+          execCap.getDigestFunction() != DigestFunction.Value.UNKNOWN &&
+          execCap.getDigestFunction() != digestFunction) {
         result.addError(
             String.format(
                 "Cannot use hash function %s with remote execution. "
                     + "Server supported function is %s",
                 digestFunction, execCap.getDigestFunction()));
+      } else if (!execCap.getDigestFunctionsList().contains(digestFunction)) {
+        result.addError(
+            String.format(
+                "Cannot use hash function %s with remote execution. "
+                    + "Server supported functions are: %s",
+                digestFunction, execCap.getDigestFunctionsList()));
       }
 
       // Check execution priority is in the supported range.
diff --git a/src/test/java/com/google/devtools/build/lib/remote/RemoteServerCapabilitiesTest.java b/src/test/java/com/google/devtools/build/lib/remote/RemoteServerCapabilitiesTest.java
index a91bd7833e5b0c..27d74a09891e80 100644
--- a/src/test/java/com/google/devtools/build/lib/remote/RemoteServerCapabilitiesTest.java
+++ b/src/test/java/com/google/devtools/build/lib/remote/RemoteServerCapabilitiesTest.java
@@ -582,6 +582,30 @@ public void testCheckClientServerCompatibility_executionCapsOnly() throws Except
     assertThat(st.isOk()).isTrue();
   }
 
+  @Test
+  public void testCheckClientServerCompatibility_executionCapsDigestFunctionsList() throws Exception {
+    ServerCapabilities caps =
+        ServerCapabilities.newBuilder()
+            .setLowApiVersion(ApiVersion.current.toSemVer())
+            .setHighApiVersion(ApiVersion.current.toSemVer())
+            .setExecutionCapabilities(
+                ExecutionCapabilities.newBuilder()
+                    .addDigestFunctions(DigestFunction.Value.MD5)
+                    .addDigestFunctions(DigestFunction.Value.SHA256)
+                    .setExecEnabled(true)
+                    .build())
+            .build();
+    RemoteOptions remoteOptions = Options.getDefaults(RemoteOptions.class);
+    remoteOptions.remoteExecutor = "server:port";
+    RemoteServerCapabilities.ClientServerCompatibilityStatus st =
+        RemoteServerCapabilities.checkClientServerCompatibility(
+            caps,
+            remoteOptions,
+            DigestFunction.Value.SHA256,
+            ServerCapabilitiesRequirement.EXECUTION);
+    assertThat(st.isOk()).isTrue();
+  }
+
   @Test
   public void testCheckClientServerCompatibility_cacheCapsOnly() throws Exception {
     ServerCapabilities caps =
diff --git a/third_party/remoteapis/build/bazel/remote/execution/v2/remote_execution.proto b/third_party/remoteapis/build/bazel/remote/execution/v2/remote_execution.proto
index 60753f78ab59a5..b21baaebb32ccc 100644
--- a/third_party/remoteapis/build/bazel/remote/execution/v2/remote_execution.proto
+++ b/third_party/remoteapis/build/bazel/remote/execution/v2/remote_execution.proto
@@ -1843,7 +1843,10 @@ message CacheCapabilities {
 
 // Capabilities of the remote execution system.
 message ExecutionCapabilities {
-  // Remote execution may only support a single digest function.
+  // Legacy field for indicating which digest function is supported by
+  // the remote execution system. Implementations should consider the
+  // repeated digest_functions field first, falling back to this
+  // singular field if unset.
   DigestFunction.Value digest_function = 1;
 
   // Whether remote execution is enabled for the particular server/instance.
@@ -1854,6 +1857,10 @@ message ExecutionCapabilities {
 
   // Supported node properties.
   repeated string supported_node_properties = 4;
+
+  // All the digest functions supported by the remote execution system.
+  // If this field is set, it MUST also contain digest_function.
+  repeated DigestFunction.Value digest_functions = 5;
 }
 
 // Details for the tool used to call the API.