diff --git a/api/src/main/java/io/minio/PutObjectArgs.java b/api/src/main/java/io/minio/PutObjectArgs.java
index 94850f942..bdc2f5869 100644
--- a/api/src/main/java/io/minio/PutObjectArgs.java
+++ b/api/src/main/java/io/minio/PutObjectArgs.java
@@ -86,7 +86,7 @@ private Builder setStream(
     }
 
     public Builder contentType(String contentType) {
-      validateNotEmptyString(contentType, "content type");
+      validateContentType(contentType);
       operations.add(args -> args.contentType = contentType);
       return this;
     }
diff --git a/api/src/main/java/io/minio/PutObjectBaseArgs.java b/api/src/main/java/io/minio/PutObjectBaseArgs.java
index 96d384c1b..aaec5e1bb 100644
--- a/api/src/main/java/io/minio/PutObjectBaseArgs.java
+++ b/api/src/main/java/io/minio/PutObjectBaseArgs.java
@@ -18,6 +18,7 @@
 
 import java.io.IOException;
 import java.util.Objects;
+import okhttp3.MediaType;
 
 /** Base argument class for {@link PutObjectArgs} and {@link UploadObjectArgs}. */
 public abstract class PutObjectBaseArgs extends ObjectWriteArgs {
@@ -60,6 +61,14 @@ public boolean preloadData() {
   @SuppressWarnings("unchecked") // Its safe to type cast to B as B is inherited by this class
   public abstract static class Builder<B extends Builder<B, A>, A extends PutObjectBaseArgs>
       extends ObjectWriteArgs.Builder<B, A> {
+    protected void validateContentType(String contentType) {
+      validateNotEmptyString(contentType, "content type");
+      if (MediaType.parse(contentType) == null) {
+        throw new IllegalArgumentException(
+            "invalid content type '" + contentType + "' as per RFC 2045");
+      }
+    }
+
     private void validateSizes(long objectSize, long partSize) {
       if (partSize > 0) {
         if (partSize < MIN_MULTIPART_SIZE) {
diff --git a/api/src/main/java/io/minio/S3Base.java b/api/src/main/java/io/minio/S3Base.java
index 5580d5745..944474af9 100644
--- a/api/src/main/java/io/minio/S3Base.java
+++ b/api/src/main/java/io/minio/S3Base.java
@@ -92,6 +92,7 @@
 import okhttp3.Callback;
 import okhttp3.Headers;
 import okhttp3.HttpUrl;
+import okhttp3.MediaType;
 import okhttp3.OkHttpClient;
 import okhttp3.Request;
 import okhttp3.RequestBody;
@@ -518,6 +519,11 @@ protected Request createRequest(
     RequestBody requestBody = null;
     if (body != null) {
       String contentType = (headers != null) ? headers.get("Content-Type") : null;
+      if (contentType != null && MediaType.parse(contentType) == null) {
+        throw new IllegalArgumentException(
+            "invalid content type '" + contentType + "' as per RFC 2045");
+      }
+
       if (body instanceof PartSource) {
         requestBody = new HttpRequestBody((PartSource) body, contentType);
       } else {
diff --git a/api/src/main/java/io/minio/UploadObjectArgs.java b/api/src/main/java/io/minio/UploadObjectArgs.java
index 6a6eef760..68775b184 100644
--- a/api/src/main/java/io/minio/UploadObjectArgs.java
+++ b/api/src/main/java/io/minio/UploadObjectArgs.java
@@ -84,7 +84,7 @@ public Builder filename(String filename) throws IOException {
     }
 
     public Builder contentType(String contentType) {
-      validateNotEmptyString(contentType, "content type");
+      validateContentType(contentType);
       operations.add(args -> args.contentType = contentType);
       return this;
     }