diff --git a/src/main/java/com/google/devtools/build/lib/analysis/platform/PlatformUtils.java b/src/main/java/com/google/devtools/build/lib/analysis/platform/PlatformUtils.java
index 79227355b01b5d..503b649886b819 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/platform/PlatformUtils.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/platform/PlatformUtils.java
@@ -29,6 +29,7 @@
 import com.google.protobuf.TextFormat;
 import com.google.protobuf.TextFormat.ParseException;
 import java.util.Comparator;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.SortedMap;
@@ -78,7 +79,19 @@ public static Platform getPlatformProto(Spawn spawn, @Nullable RemoteOptions rem
     Platform.Builder platformBuilder = Platform.newBuilder();
 
     if (!spawn.getCombinedExecProperties().isEmpty()) {
-      for (Map.Entry<String, String> entry : spawn.getCombinedExecProperties().entrySet()) {
+      Map<String, String> combinedExecProperties;
+      // Apply default exec properties if the execution platform does not already set
+      // exec_properties
+      if (spawn.getExecutionPlatform() == null
+          || spawn.getExecutionPlatform().execProperties().isEmpty()) {
+        combinedExecProperties = new HashMap<>();
+        combinedExecProperties.putAll(defaultExecProperties);
+        combinedExecProperties.putAll(spawn.getCombinedExecProperties());
+      } else {
+        combinedExecProperties = spawn.getCombinedExecProperties();
+      }
+
+      for (Map.Entry<String, String> entry : combinedExecProperties.entrySet()) {
         platformBuilder.addPropertiesBuilder().setName(entry.getKey()).setValue(entry.getValue());
       }
     } else if (spawn.getExecutionPlatform() != null
diff --git a/src/test/java/com/google/devtools/build/lib/analysis/platform/PlatformUtilsTest.java b/src/test/java/com/google/devtools/build/lib/analysis/platform/PlatformUtilsTest.java
index 0b013fbdb81706..fc15ae5d79f493 100644
--- a/src/test/java/com/google/devtools/build/lib/analysis/platform/PlatformUtilsTest.java
+++ b/src/test/java/com/google/devtools/build/lib/analysis/platform/PlatformUtilsTest.java
@@ -17,12 +17,14 @@
 import static com.google.common.truth.Truth.assertThat;
 
 import build.bazel.remote.execution.v2.Platform;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.lib.actions.ExecutionRequirements;
 import com.google.devtools.build.lib.actions.Spawn;
 import com.google.devtools.build.lib.exec.util.SpawnBuilder;
 import com.google.devtools.build.lib.remote.options.RemoteOptions;
 import com.google.devtools.common.options.Options;
+import java.util.AbstractMap;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
@@ -45,8 +47,9 @@ private static String platformOptionsString() {
 
   private static RemoteOptions remoteOptions() {
     RemoteOptions remoteOptions = Options.getDefaults(RemoteOptions.class);
-    remoteOptions.remoteDefaultPlatformProperties = platformOptionsString();
-
+    remoteOptions.remoteDefaultExecProperties =
+        ImmutableList.of(
+            new AbstractMap.SimpleEntry<>("b", "2"), new AbstractMap.SimpleEntry<>("a", "1"));
     return remoteOptions;
   }
 
@@ -93,7 +96,7 @@ public void testParsePlatformSortsProperties_execProperties() throws Exception {
             .addProperties(Platform.Property.newBuilder().setName("zz").setValue("66"))
             .build();
     // execProperties are sorted by key
-    assertThat(PlatformUtils.getPlatformProto(s, remoteOptions())).isEqualTo(expected);
+    assertThat(PlatformUtils.getPlatformProto(s, null)).isEqualTo(expected);
   }
 
   @Test
@@ -115,4 +118,28 @@ public void testGetPlatformProto_differentiateWorkspace() throws Exception {
     // execProperties are sorted by key
     assertThat(PlatformUtils.getPlatformProto(s, remoteOptions())).isEqualTo(expected);
   }
+
+  @Test
+  public void getPlatformProto_mergeTargetExecPropertiesWithPlatform() throws Exception {
+    Spawn spawn = new SpawnBuilder("dummy").withExecProperties(ImmutableMap.of("c", "3")).build();
+    Platform expected =
+        Platform.newBuilder()
+            .addProperties(Platform.Property.newBuilder().setName("a").setValue("1"))
+            .addProperties(Platform.Property.newBuilder().setName("b").setValue("2"))
+            .addProperties(Platform.Property.newBuilder().setName("c").setValue("3"))
+            .build();
+    assertThat(PlatformUtils.getPlatformProto(spawn, remoteOptions())).isEqualTo(expected);
+  }
+
+  @Test
+  public void getPlatformProto_targetExecPropertiesConflictWithPlatform_override()
+      throws Exception {
+    Spawn spawn = new SpawnBuilder("dummy").withExecProperties(ImmutableMap.of("b", "3")).build();
+    Platform expected =
+        Platform.newBuilder()
+            .addProperties(Platform.Property.newBuilder().setName("a").setValue("1"))
+            .addProperties(Platform.Property.newBuilder().setName("b").setValue("3"))
+            .build();
+    assertThat(PlatformUtils.getPlatformProto(spawn, remoteOptions())).isEqualTo(expected);
+  }
 }