diff --git a/coverage-report/src/test/java/org/jooby/issues/Issue730.java b/coverage-report/src/test/java/org/jooby/issues/Issue730.java
new file mode 100644
index 0000000000..12824a46df
--- /dev/null
+++ b/coverage-report/src/test/java/org/jooby/issues/Issue730.java
@@ -0,0 +1,23 @@
+package org.jooby.issues;
+
+import org.jooby.test.ServerFeature;
+import org.junit.Test;
+
+public class Issue730 extends ServerFeature {
+
+  {
+    get("/730", (req, rsp) -> {
+      rsp.header("content-type", "application/json");
+      rsp.send("{\"issue\": \"730\"}");
+    });
+
+  }
+
+  @Test
+  public void contentTypeShouldWorkFromSetHeader() throws Exception {
+    request().get("/730")
+        .execute()
+        .header("Content-Type", "application/json;charset=utf-8");
+  }
+
+}
diff --git a/jooby/src/main/java/org/jooby/internal/ResponseImpl.java b/jooby/src/main/java/org/jooby/internal/ResponseImpl.java
index 9d87303e23..a070bab7bf 100644
--- a/jooby/src/main/java/org/jooby/internal/ResponseImpl.java
+++ b/jooby/src/main/java/org/jooby/internal/ResponseImpl.java
@@ -446,6 +446,10 @@ private Response setHeader(final String name, final Object value) {
           }
           rsp.header(LOCATION, location);
         } else {
+          if ("Content-Type".equalsIgnoreCase(name)) {
+            // keep type reference
+            this.type = MediaType.valueOf(value.toString());
+          }
           rsp.header(name, Headers.encode(value));
         }
       }