diff --git a/akka-http-core/src/main/scala/akka/http/impl/engine/parsing/HttpHeaderParser.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/parsing/HttpHeaderParser.scala
index 5d7b0a4bef..6d0194995c 100644
--- a/akka-http-core/src/main/scala/akka/http/impl/engine/parsing/HttpHeaderParser.scala
+++ b/akka-http-core/src/main/scala/akka/http/impl/engine/parsing/HttpHeaderParser.scala
@@ -451,7 +451,7 @@ private[http] object HttpHeaderParser {
       // TODO: optimize by running the header value parser directly on the input ByteString (rather than an extracted String)
       val (headerValue, endIx) = scanHeaderValue(input, valueStart, valueStart + maxHeaderValueLength)()
       val trimmedHeaderValue = headerValue.trim
-      val header = HeaderParser.dispatch(new HeaderParser(trimmedHeaderValue), headerName) match {
+      val header = HeaderParser.parseFull(headerName, trimmedHeaderValue) match {
         case Right(h) ⇒ h
         case Left(error) ⇒
           onIllegalHeader(error.withSummaryPrepended(s"Illegal '$headerName' header"))
diff --git a/akka-http-core/src/main/scala/akka/http/impl/model/parser/HeaderParser.scala b/akka-http-core/src/main/scala/akka/http/impl/model/parser/HeaderParser.scala
index b509523a1c..c40cacb515 100644
--- a/akka-http-core/src/main/scala/akka/http/impl/model/parser/HeaderParser.scala
+++ b/akka-http-core/src/main/scala/akka/http/impl/model/parser/HeaderParser.scala
@@ -67,6 +67,19 @@ private[http] class HeaderParser(val input: ParserInput) extends Parser with Dyn
 private[http] object HeaderParser {
   object RuleNotFoundException extends SingletonException
 
+  def parseFull(headerName: String, value: String): HeaderParser#Result = {
+    import akka.parboiled2.EOI
+    val v = value + EOI // this makes sure the parser isn't broken even if there's no trailing garbage in this value
+    val parser = new HeaderParser(v)
+    dispatch(parser, headerName) match {
+      case r @ Right(_) if parser.cursor == v.length ⇒ r
+      case r @ Right(_) ⇒
+        Left(ErrorInfo("Header parsing error",
+          s"Rule for $headerName accepted trailing garbage. Is the parser missing a trailing EOI?"))
+      case Left(e) ⇒ Left(e.copy(summary = e.summary.filterNot(_ == EOI), detail = e.detail.filterNot(_ == EOI)))
+    }
+  }
+
   val (dispatch, ruleNames) = DynamicRuleDispatch[HeaderParser, HttpHeader :: HNil](
     "accept",
     "accept-charset",
diff --git a/akka-http-core/src/main/scala/akka/http/impl/model/parser/SimpleHeaders.scala b/akka-http-core/src/main/scala/akka/http/impl/model/parser/SimpleHeaders.scala
index bbf9912606..f8dd2f8ee7 100644
--- a/akka-http-core/src/main/scala/akka/http/impl/model/parser/SimpleHeaders.scala
+++ b/akka-http-core/src/main/scala/akka/http/impl/model/parser/SimpleHeaders.scala
@@ -37,7 +37,7 @@ private[parser] trait SimpleHeaders { this: Parser with CommonRules with CommonA
 
   // http://www.w3.org/TR/cors/#access-control-allow-origin-response-header
   def `access-control-allow-origin` = rule(
-    ws('*') ~ push(`Access-Control-Allow-Origin`.`*`)
+    ws('*') ~ EOI ~ push(`Access-Control-Allow-Origin`.`*`)
       | `origin-list-or-null` ~ EOI ~> (origins ⇒ `Access-Control-Allow-Origin`.forRange(HttpOriginRange(origins: _*))))
 
   // http://www.w3.org/TR/cors/#access-control-expose-headers-response-header
@@ -108,7 +108,7 @@ private[parser] trait SimpleHeaders { this: Parser with CommonRules with CommonA
 
   // http://tools.ietf.org/html/rfc7231#section-5.1.1
   def `expect` = rule {
-    ignoreCase("100-continue") ~ OWS ~ push(Expect.`100-continue`)
+    ignoreCase("100-continue") ~ OWS ~ EOI ~ push(Expect.`100-continue`)
   }
 
   // http://tools.ietf.org/html/rfc7234#section-5.3
@@ -126,7 +126,7 @@ private[parser] trait SimpleHeaders { this: Parser with CommonRules with CommonA
 
   // http://tools.ietf.org/html/rfc7232#section-3.1
   def `if-match` = rule(
-    ws('*') ~ push(`If-Match`.`*`)
+    ws('*') ~ EOI ~ push(`If-Match`.`*`)
       | oneOrMore(`entity-tag`).separatedBy(listSep) ~ EOI ~> (tags ⇒ `If-Match`(EntityTagRange(tags: _*))))
 
   // http://tools.ietf.org/html/rfc7232#section-3.3
@@ -134,7 +134,7 @@ private[parser] trait SimpleHeaders { this: Parser with CommonRules with CommonA
 
   // http://tools.ietf.org/html/rfc7232#section-3.2
   def `if-none-match` = rule {
-    ws('*') ~ push(`If-None-Match`.`*`) |
+    ws('*') ~ EOI ~ push(`If-None-Match`.`*`) |
       oneOrMore(`entity-tag`).separatedBy(listSep) ~ EOI ~> (tags ⇒ `If-None-Match`(EntityTagRange(tags: _*)))
   }
 
@@ -175,7 +175,7 @@ private[parser] trait SimpleHeaders { this: Parser with CommonRules with CommonA
   }
 
   // http://tools.ietf.org/html/rfc7231#section-7.4.2
-  def server = rule { products ~> (Server(_)) }
+  def server = rule { products ~ EOI ~> (Server(_)) }
 
   // http://tools.ietf.org/html/rfc7230#section-3.3.1
   def `transfer-encoding` = rule {
@@ -189,7 +189,7 @@ private[parser] trait SimpleHeaders { this: Parser with CommonRules with CommonA
 
   // http://tools.ietf.org/html/rfc7230#section-6.7
   def upgrade = rule {
-    oneOrMore(protocol).separatedBy(listSep) ~> (Upgrade(_))
+    oneOrMore(protocol).separatedBy(listSep) ~ EOI ~> (Upgrade(_))
   }
 
   def protocol = rule {
@@ -197,7 +197,7 @@ private[parser] trait SimpleHeaders { this: Parser with CommonRules with CommonA
   }
 
   // http://tools.ietf.org/html/rfc7231#section-5.5.3
-  def `user-agent` = rule { products ~> (`User-Agent`(_)) }
+  def `user-agent` = rule { products ~ EOI ~> (`User-Agent`(_)) }
 
   // http://tools.ietf.org/html/rfc7235#section-4.1
   def `www-authenticate` = rule {
diff --git a/akka-http-core/src/main/scala/akka/http/scaladsl/model/HttpHeader.scala b/akka-http-core/src/main/scala/akka/http/scaladsl/model/HttpHeader.scala
index 0ffc81ecbe..79b71db1ca 100644
--- a/akka-http-core/src/main/scala/akka/http/scaladsl/model/HttpHeader.scala
+++ b/akka-http-core/src/main/scala/akka/http/scaladsl/model/HttpHeader.scala
@@ -60,7 +60,7 @@ object HttpHeader {
       parser.`header-field-value`.run() match {
         case Success(preProcessedValue) ⇒
           try {
-            HeaderParser.dispatch(new HeaderParser(preProcessedValue), name.toLowerCase) match {
+            HeaderParser.parseFull(name.toLowerCase, preProcessedValue) match {
               case Right(header) ⇒ ParsingResult.Ok(header, Nil)
               case Left(info) ⇒
                 val errors = info.withSummaryPrepended(s"Illegal HTTP header '$name'") :: Nil
diff --git a/akka-http-core/src/test/scala/akka/http/impl/model/parser/HttpHeaderSpec.scala b/akka-http-core/src/test/scala/akka/http/impl/model/parser/HttpHeaderSpec.scala
index 5de9aaf4a7..3f3e9dd77c 100644
--- a/akka-http-core/src/test/scala/akka/http/impl/model/parser/HttpHeaderSpec.scala
+++ b/akka-http-core/src/test/scala/akka/http/impl/model/parser/HttpHeaderSpec.scala
@@ -4,6 +4,7 @@
 
 package akka.http.impl.model.parser
 
+import akka.http.scaladsl.model.HttpHeader.ParsingResult
 import org.scalatest.{ Matchers, FreeSpec }
 import org.scalatest.matchers.{ Matcher, MatchResult }
 import akka.http.impl.util._