diff --git a/opm/parser/eclipse/Parser/Parser.cpp b/opm/parser/eclipse/Parser/Parser.cpp
index 3ffd2bb47..35ba99bf6 100644
--- a/opm/parser/eclipse/Parser/Parser.cpp
+++ b/opm/parser/eclipse/Parser/Parser.cpp
@@ -160,8 +160,9 @@ namespace Opm {
     }
 
     bool Parser::isRecognizedKeyword(const std::string& deckKeywordName) const {
-        if (!ParserKeyword::validDeckName(deckKeywordName, /*acceptLowerCase=*/true))
+        if (!ParserKeyword::validDeckName(deckKeywordName)) {
             return false;
+        }
 
         if (m_deckParserKeywords.count(deckKeywordName) > 0)
             return true;
@@ -309,8 +310,8 @@ namespace Opm {
                                                                   "The keyword " + parserState->rawKeyword->getKeywordName() + " is ignored - this might potentially affect the results");
                         } else {
                             DeckKeywordPtr deckKeyword(new DeckKeyword(parserState->rawKeyword->getKeywordName(), false));
-                            deckKeyword->setLocation(parserState->rawKeyword->getFilename(),
-                                                     parserState->rawKeyword->getLineNR());
+			    deckKeyword->setLocation(parserState->rawKeyword->getFilename(),
+						     parserState->rawKeyword->getLineNR());
                             parserState->deck->addKeyword(deckKeyword);
                             parserState->parserLog.addWarning(parserState->dataFile.string(),
                                                               parserState->rawKeyword->getLineNR(),
diff --git a/opm/parser/eclipse/Parser/ParserKeyword.cpp b/opm/parser/eclipse/Parser/ParserKeyword.cpp
index 4b104d6ca..70be832ef 100644
--- a/opm/parser/eclipse/Parser/ParserKeyword.cpp
+++ b/opm/parser/eclipse/Parser/ParserKeyword.cpp
@@ -202,11 +202,11 @@ namespace Opm {
     }
 
 
-    bool ParserKeyword::validNameStart(const std::string& name, bool acceptLowerCaseLetters) {
+    bool ParserKeyword::validNameStart(const std::string& name) {
         if (name.length() > ParserConst::maxKeywordLength)
             return false;
 
-        if (!isupper(name[0]) && !(acceptLowerCaseLetters && islower(name[0])))
+        if (!isupper(name[0]))
             return false;
         
         return true;
@@ -241,14 +241,13 @@ namespace Opm {
         return result;
     }
 
-    bool ParserKeyword::validDeckName(const std::string& name, bool acceptLowerCaseLetters) {
-        if (!validNameStart(name, acceptLowerCaseLetters))
+    bool ParserKeyword::validDeckName(const std::string& name) {
+        if (!validNameStart(name))
             return false;
 
         for (size_t i = 1; i < name.length(); i++) {
             char c = name[i];
             if (!isupper(c) &&
-                !(acceptLowerCaseLetters && islower(c)) &&
                 !isdigit(c) &&
                 c != '-' &&
                 c != '_' &&
diff --git a/opm/parser/eclipse/Parser/ParserKeyword.hpp b/opm/parser/eclipse/Parser/ParserKeyword.hpp
index 7123c16c4..7ff47fee4 100644
--- a/opm/parser/eclipse/Parser/ParserKeyword.hpp
+++ b/opm/parser/eclipse/Parser/ParserKeyword.hpp
@@ -106,7 +106,7 @@ namespace Opm {
 
         static std::string getDeckName(const std::string& rawString);
         static bool validInternalName(const std::string& name);
-        static bool validDeckName(const std::string& name, bool acceptLowerCaseLetters = false);
+        static bool validDeckName(const std::string& name);
         bool hasMatchRegex() const;
         void setMatchRegex(const std::string& deckNameRegexp);
         bool matches(const std::string& deckKeywordName) const;
@@ -162,7 +162,7 @@ namespace Opm {
         ParserKeywordActionEnum m_action;
         std::string m_Description;
 
-        static bool validNameStart(const std::string& name, bool acceptLowerCaseLetters);
+        static bool validNameStart(const std::string& name);
         void initDeckNames( const Json::JsonObject& jsonConfig );
         void initSectionNames( const Json::JsonObject& jsonConfig );
         void initMatchRegex( const Json::JsonObject& jsonObject );
diff --git a/opm/parser/eclipse/RawDeck/RawKeyword.cpp b/opm/parser/eclipse/RawDeck/RawKeyword.cpp
index 9a5aa7abb..c45c57a2c 100644
--- a/opm/parser/eclipse/RawDeck/RawKeyword.cpp
+++ b/opm/parser/eclipse/RawDeck/RawKeyword.cpp
@@ -138,7 +138,7 @@ namespace Opm {
     }
 
     bool RawKeyword::isValidKeyword(const std::string& keywordCandidate) {
-        return ParserKeyword::validDeckName(keywordCandidate, /*acceptLowerCase=*/true);
+        return ParserKeyword::validDeckName(keywordCandidate);
     }
 
 
diff --git a/opm/parser/eclipse/RawDeck/tests/RawKeywordTests.cpp b/opm/parser/eclipse/RawDeck/tests/RawKeywordTests.cpp
index e00e45cc6..85642f512 100644
--- a/opm/parser/eclipse/RawDeck/tests/RawKeywordTests.cpp
+++ b/opm/parser/eclipse/RawDeck/tests/RawKeywordTests.cpp
@@ -62,11 +62,7 @@ BOOST_AUTO_TEST_CASE(RawKeywordSetKeywordInitialWhitespaceInKeywordThrows) {
 }
 
 BOOST_AUTO_TEST_CASE(constructor_mixedCaseName_throws) {
-    // raw keywords may be lower-case even if this is not allowed in valid deck
-    // names... (this will produce a warning if the deck is checked.)
-    RawKeyword("Test", Raw::SLASH_TERMINATED , "FILE" , 10U);
-    RawKeyword("test", Raw::SLASH_TERMINATED , "FILE" , 10U);
-    BOOST_CHECK_THROW(RawKeyword keyword("1test", Raw::SLASH_TERMINATED , "FILE" , 10U), std::invalid_argument);
+    BOOST_CHECK_THROW(RawKeyword("Test", Raw::SLASH_TERMINATED , "FILE" , 10U), std::invalid_argument);
 }
 
 BOOST_AUTO_TEST_CASE(RawKeywordSetKeywordInitialTabInKeywordThrows) {