diff --git a/processing/src/main/java/org/apache/druid/math/expr/ExprEval.java b/processing/src/main/java/org/apache/druid/math/expr/ExprEval.java
index d390d616ba20..3634734bfe14 100644
--- a/processing/src/main/java/org/apache/druid/math/expr/ExprEval.java
+++ b/processing/src/main/java/org/apache/druid/math/expr/ExprEval.java
@@ -33,6 +33,7 @@
 import org.apache.druid.segment.nested.StructuredData;
 
 import javax.annotation.Nullable;
+import java.math.BigDecimal;
 import java.nio.ByteBuffer;
 import java.util.Arrays;
 import java.util.List;
@@ -388,7 +389,7 @@ public static ExprEval bestEffortOf(@Nullable Object val)
       return new StringExprEval((String) val);
     }
     if (val instanceof Number) {
-      if (val instanceof Float || val instanceof Double) {
+      if (val instanceof Float || val instanceof Double || val instanceof BigDecimal) {
         return new DoubleExprEval((Number) val);
       }
       return new LongExprEval((Number) val);
diff --git a/processing/src/test/java/org/apache/druid/math/expr/EvalTest.java b/processing/src/test/java/org/apache/druid/math/expr/EvalTest.java
index f03956022226..b18b8cff3ea1 100644
--- a/processing/src/test/java/org/apache/druid/math/expr/EvalTest.java
+++ b/processing/src/test/java/org/apache/druid/math/expr/EvalTest.java
@@ -33,6 +33,7 @@
 import org.junit.BeforeClass;
 import org.junit.Test;
 
+import java.math.BigDecimal;
 import java.nio.ByteBuffer;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -1380,6 +1381,9 @@ public void testBestEffortOf()
     assertBestEffortOf(1L, ExpressionType.LONG, 1L);
     assertBestEffortOf(1, ExpressionType.LONG, 1L);
 
+    // BigDecimal
+    assertBestEffortOf(new BigDecimal("0.034"), ExpressionType.DOUBLE, 0.034);
+
     // by default, booleans are handled as longs
     assertBestEffortOf(true, ExpressionType.LONG, 1L);
     assertBestEffortOf(Arrays.asList(true, false), ExpressionType.LONG_ARRAY, new Object[]{1L, 0L});