diff --git a/glslang/MachineIndependent/Intermediate.cpp b/glslang/MachineIndependent/Intermediate.cpp
index 389d4a9b..091158bf 100644
--- a/glslang/MachineIndependent/Intermediate.cpp
+++ b/glslang/MachineIndependent/Intermediate.cpp
@@ -836,8 +836,10 @@ bool TIntermBinary::promote(TInfoSink& infoSink)
     // Fix precision qualifiers
     if (right->getQualifier().precision > getQualifier().precision)
         getQualifier().precision = right->getQualifier().precision;
-    left->propagatePrecision(getQualifier().precision);
-    right->propagatePrecision(getQualifier().precision);
+    if (getQualifier().precision != EpqNone) {
+        left->propagatePrecision(getQualifier().precision);
+        right->propagatePrecision(getQualifier().precision);
+    }
 
     //
     // Array operations.
@@ -1125,7 +1127,8 @@ void TIntermTyped::propagatePrecision(TPrecisionQualifier newPrecision)
     //    comma operator:  just through the last operand
     //    ":?" and ",": where is this triggered?
     //    built-in function calls: how much to propagate to arguments?
-    //    performance: don't do this for desktop profiles
+    //    length()?
+    //    indexing?
 }
 
 bool CompareStructure(const TType& leftNodeType, constUnion* rightUnionArray, constUnion* leftUnionArray)
diff --git a/glslang/MachineIndependent/ParseHelper.cpp b/glslang/MachineIndependent/ParseHelper.cpp
index 13b3bc3d..5c748019 100644
--- a/glslang/MachineIndependent/ParseHelper.cpp
+++ b/glslang/MachineIndependent/ParseHelper.cpp
@@ -55,11 +55,7 @@ TParseContext::TParseContext(TSymbolTable& symt, TIntermediate& interm, EShLangu
     // Default precisions for version 110, to be overridden for 
     // other versions/profiles/stage combinations
     for (int type = 0; type < EbtNumTypes; ++type)
-        defaultPrecision[type] = EpqHigh;
-    
-    defaultPrecision[EbtVoid]   = EpqNone;
-    defaultPrecision[EbtDouble] = EpqNone;
-    defaultPrecision[EbtBool]   = EpqNone;
+        defaultPrecision[type] = EpqNone;
 }
 
 //
diff --git a/glslang/MachineIndependent/glslang.l b/glslang/MachineIndependent/glslang.l
index 86bac745..cb9a0356 100644
--- a/glslang/MachineIndependent/glslang.l
+++ b/glslang/MachineIndependent/glslang.l
@@ -734,9 +734,6 @@ void SetVersion(int version)
     parseContext.version = version;
 
 	if (version == 100 || version == 300) {
-	    for (int type = 0; type < EbtNumTypes; ++type)
-		    parseContext.defaultPrecision[type] = EpqNone;
-
 	    if (parseContext.language == EShLangVertex) {
 			parseContext.defaultPrecision[EbtInt] = EpqHigh;
 			parseContext.defaultPrecision[EbtFloat] = EpqHigh;
diff --git a/glslang/MachineIndependent/glslang.y b/glslang/MachineIndependent/glslang.y
index 62635429..f10d0c7b 100644
--- a/glslang/MachineIndependent/glslang.y
+++ b/glslang/MachineIndependent/glslang.y
@@ -2442,17 +2442,20 @@ precision_qualifier
     : HIGH_PRECISION {
         parseContext.profileRequires($1.line, ENoProfile, 130, 0, "highp precision qualifier");
         $$.init($1.line);
-		$$.qualifier.precision = EpqHigh;
+        if (parseContext.profile == EEsProfile)
+		    $$.qualifier.precision = EpqHigh;
     }
     | MEDIUM_PRECISION {
         parseContext.profileRequires($1.line, ENoProfile, 130, 0, "mediump precision qualifier");
         $$.init($1.line);
-		$$.qualifier.precision = EpqMedium;
+        if (parseContext.profile == EEsProfile)
+	    	$$.qualifier.precision = EpqMedium;
     }
     | LOW_PRECISION {
         parseContext.profileRequires($1.line, ENoProfile, 130, 0, "lowp precision qualifier");
         $$.init($1.line);
-		$$.qualifier.precision = EpqLow;
+        if (parseContext.profile == EEsProfile)
+    		$$.qualifier.precision = EpqLow;
     }
     ;